TW201603242A - Flash memory devices and methods for performing concurrent operations - Google Patents

Abstract

A flash memory device comprising: a first Serial Peripheral Interface ("SPI") flash memory die comprising a first die identifier and a first set of SPI pins; a second SPI flash memory die comprising a second die identifier and a second set of SPI pins; and a package containing the first SPI flash memory die and the second SPI flash memory die in a stacked arrangement, and having a set of SPI package pins coupled in parallel to the first and second set of SPI pins.

Description

Flash memory device and method of performing synchronous operation

The present invention relates to a flash memory, and more particularly to a flash memory device utilizing stacked memory dies and a serial peripheral interface.

Tandem flash memory has become a popular alternative to traditional side-by-side flash memory. Tandem flash memory offers many advantages, including small package area, low pin count, simplified printed circuit board layout, low power consumption, comparable performance to side-by-side flash memory, and corresponding device and system level costs. Lower. The serial peripheral interface is widely used in tandem flash memory, and can be connected by a single-element or multi-bit serial peripheral interface (including multi-bit instructions and/or address input and multi-bit data output). The configuration of the device is currently particularly popular. The serial peripheral interface has many advantages: the peripheral serial interface allows for wide compatibility, while the multi-bit serial peripheral interface allows for fast "code mapping" at high timing speeds when combined with some flash memory. (code shadowing)" to random access memory and "in-place execution (XIP)" and other code storage applications.

Tandem flash memory typically provides 512Kb to 1Gb of capacity. However, for high-density tandem flash memory, the demand for lower cost per bit continues to increase. Among them, a single high-density grain is feasible but its cost is high, so the same type of low-density grain stack can be formed into a high-density string. A columnar flash memory device is included as an alternative. For example, two identical types of tandem flash memory chips having a density of 256 Mb can be stacked to form a device with a capacity of 512 Mb (2 x 256 Mb), or four identical types of tandem with a density of 256 Mb. The flash memory die is stacked to form a device having a capacity of 1 Gb (4 x 256 Mb).

In addition, different types of flash memory dies can be stacked to form a single memory device having different characteristics. Flash memory usually has NOR flash memory and NAND flash memory. In NOR flash memory, each memory cell is connected between bit line and ground, and in NAND flash memory. A plurality of memory cells are connected in series between the bit line and the ground. Among them, NOR flash memory generally has low density, high read speed, low write speed, low erase speed and random access, while NAND flash memory generally has high density, medium read speed, and high Page write speed, high erase speed, and indirect or I/O access. NOR flash memory because of random access, the microprocessor usually uses NOR flash memory for fast "code mapping" to random access memory and "in-place execution" applications, while NAND flash memory Due to its high-speed sequence writing capability and high-density but low-cost features, it is especially suitable for systems with high data storage capacity requirements. In addition, certain types of NAND flash memory have been improved to provide SPI-NOR flash memory-like features in code mapping applications.

The operating techniques of a tandem peripheral interface flash memory device with stacked dies are still not perfect. "Spansion Inc., Data Sheet, S70FL256P 256-Mbit CMOS 3.0 Volt Flash Memory with 104-MHz SPI Multi I/O Bus, Revision 05, January 30, 2013" After the two identical 128Mb dies are stacked, the individual /CS pins are soldered to the serial peripheral memory flash memory device formed by different corresponding pins on the package. However, it is disadvantageous that it needs to provide and manage multiple /CS control signals through the controller. In addition, the extra /CS pin requirements also make the serial peripheral interface flash memory device unable to perform eight-pin. Package.

"Micron Technology Inc., N25Q512A 1.8V, Multiple I/O Serial Flash Memory, September 2013" reveals that after stacking two different crystal grains, in addition to the memory reading and erasing operations, the user The angle can be viewed as a single device flash memory device. However, although the above device can perform the operation of the quaternary I/O serial peripheral interface agreement in the eight-pin package, the manufacturing cost thereof is often high due to its complicated special design.

The present invention provides a flash memory device having the advantages of Serial Peripheral Interface (SPI) flash memory, as well as higher data storage capacity, and, in some embodiments, is compatible with In-place execution and application of code mapping. The invention includes the following exemplary embodiments.

An embodiment of the present invention provides a flash memory device including: a first serial peripheral interface flash memory die having a first die identifier and a first serial peripheral interface pin group; a second serial peripheral interface flash memory die having a second die identifier and a second serial peripheral interface pin set; and a package having a first serial peripheral interface arranged in a stacked configuration a flash memory die and a second series of peripheral interface flash memory die, and a series of peripheral interface package pin sets, and the first series of peripheral interfaces The face pin group and the second series peripheral interface pin group are coupled in parallel.

Another embodiment of the present invention provides a method for performing a synchronous operation in a tandem peripheral interface flash memory device, wherein the serial peripheral interface flash memory device has a serial peripheral package including a wafer select pin Pin group. The serial peripheral interface flash memory device suitable for use in the above method comprises a first serial peripheral interface flash memory die having a first die identifier and a first serial peripheral interface pin set; a second serial peripheral interface flash memory die having a second die identifier and a second serial peripheral interface pin set; the first serial peripheral interface flash memory die and the second string The column peripheral interface flash memory die stack, and the first serial peripheral interface pin group and the second serial peripheral interface pin group are coupled in parallel with the serial peripheral interface package pin group. The method includes receiving, by a chip selection pin of the serial peripheral interface flash memory device, a first chip selection active signal, wherein the first chip selects an active signal system and supplies the data to the first serial peripheral memory die and the second string in parallel Column peripheral interface memory die; and in combination with receiving the first wafer to select an active signal, performing the first on the first serial peripheral interface flash memory die and the second serial peripheral interface flash memory die a die select command to enable the first serial peripheral interface flash memory die to respond to a series of peripheral interface command sets, and to enable the second serial peripheral interface flash memory die to respond only to a general instruction subset The general instruction subset is a subset of the serial peripheral interface instruction set and includes a die select instruction. The method further includes receiving a first wafer selection stop signal from the chip select pin of the serial peripheral interface flash memory device to terminate the first serial peripheral interface flash memory die and the second serial peripheral interface flash memory Execution of the first die select command on the die. The method further includes when the first serial peripheral interface When the flash memory die is enabled to respond to the serial peripheral interface command set, the second chip select active signal is received on the chip select pin of the serial peripheral interface flash memory device, and the second chip selects the active signal to be provided in parallel. Up to the first serial peripheral memory flash memory die and the second serial peripheral interface flash memory die; and the step of receiving the second chip to select the active signal, in the first serial peripheral interface flash memory The first serial peripheral interface instruction executing a non-generic instruction on the die causes an internal self-timed operation to be performed. The method further includes receiving, by the chip select pin of the serial peripheral interface flash memory device, a second chip select stop signal to terminate the first serial peripheral interface command on the first serial peripheral interface flash memory die, but The internal self-timed operation is not terminated. The method further includes receiving a third chip selection active signal on the chip selection pin of the serial peripheral interface flash memory device, and the third chip selection active signal is provided in parallel to the first serial peripheral interface flash memory die and a second series of peripheral interface flash memory dies; and a step of selecting an active signal in conjunction with receiving the third wafer, the first array of peripheral interface flash memory dies and the second series of peripheral interface flash memory crystals Performing a second die select command on the granule to enable the second serial peripheral interface flash memory die to respond to the serial peripheral interface command set, and enabling the first serial peripheral interface flash memory die response general instruction Subset. The method further includes receiving, by the chip selection pin of the serial peripheral interface flash memory device, a third wafer selection stop signal to terminate the first serial peripheral interface flash memory die and the second serial peripheral interface flash memory. Execution of a second die selection command on the bulk die. The method further includes receiving, when the second serial peripheral interface flash memory die is enabled in response to the serial peripheral interface instruction set, receiving the fourth chip selection active signal in the chip selection pin of the serial peripheral interface flash memory device , the first The four-chip selection active signal is provided in parallel to the first serial peripheral interface flash memory die and the second serial peripheral interface flash memory die; and the step of receiving the fourth chip to select the active signal, The second serial peripheral interface command is executed on the two serial peripheral flash memory die, and the internal self-timing operation is performed on the first serial peripheral memory die. The method further includes receiving, by the chip select pin of the serial peripheral memory device, a fourth wafer select stop signal to terminate the second serial peripheral interface command.

10, 20, 70, 90, 100‧‧‧ Serial peripheral interface flash memory devices

11, 12, 13, 14, 21, 22, 23, 24, 72, 74, 92, 94, 102, 104‧‧‧ Serialized peripheral interface flash memory grains

60, 61, 62, 64, 66, 68‧ ‧ steps flow

71, 91, 101‧‧‧ package body

73‧‧‧ Compartment

75, 95, 105‧‧‧ adhesives

76, 96, 106‧‧‧ Thermal pad

77, 78, 97, 107, 108‧‧‧ areas

81, 82, 83, 84, 98, 99, 111, 112, 113, 114‧‧‧ leads

93, 103‧‧‧Materials

1 is a block diagram showing a tandem peripheral interface flash memory device having a stacked serial peripheral flash memory die according to an embodiment of the invention.

2 is a block diagram showing a tandem peripheral interface flash memory device having a stacked serial peripheral memory flash memory die according to another embodiment of the present invention.

Figure 3 is a block diagram showing the die select command.

Figure 4 is a block diagram showing the execution of a sequence of synchronous operation instructions in a tandem peripheral interface flash memory device having stacked serial peripheral flash memory dies.

Figure 5 is a block diagram showing another sequence of instructions for executing a synchronous operation in a tandem peripheral interface flash memory device having stacked serial peripheral flash memory dies.

Figure 6 is a flow chart showing the operation of the serial peripheral interface flash memory die in response to the die select command.

Figure 7 is a side plan view showing a die stacking technique using a spacer between the dies.

Figure 8 is a side plan view showing a die stacking technique using grain interleaving.

Figure 9 is a side plan view showing a die stacking technique using dies of different sizes.

As used herein, "serial peripheral interface flash memory die" (hereinafter referred to as flash memory die) refers to an integrated circuit die including any type of flash memory array, which is configured to be compatible with strings. One of the column peripheral interface protocols is a pin. Any number of flash memory dies can be stacked and packaged using any desired multi-chip package technology. Among them, each of the flash memory dies stacked in the package may be individually assigned a unique die identifier (Die ID) during manufacturing, and during the normal operation, through the die selection command (Die Select) Specifying different die identifiers so that one of the stacked flash memory dies responds to subsequent instructions on the serial peripheral interface and enables other flash memory dies stacked in the package to respond only to the string Some general-purpose instructions (such as die select instructions) that follow the peripheral interface.

As used herein, "pin" refers to a conductive element that is used to directly or indirectly externally electrically connect to a flash memory die, including either a conductive element on a die (eg, a bonding pad), or A conductive element (eg, a recessed contact, a flush contact, a projecting contact) embedded in or on the package.

As used herein, "serial peripheral interface pin" and "serial peripheral interface package pin" refer to pins that are compatible with the serial peripheral interface protocol. According to the serial peripheral interface protocol, the six pins can be configured as a single serial SPI, a dual serial SPI, a quad SPI, or a quaternary peripheral interface. (Quad Peripheral Interphase, QPI, also known as Serial Quad Interface (SQI)), and can include single or multi-bit instructions and/or address inputs as well as single or multiple bits The data input and/or output, whose configurability may include any subsets that are expected in the above structure. The six-pin system provides wafer selection / CS, timing CLK, configurable pin DI (IO ₀ ), configurable pin DO (IO ₁ ), configurable pin / WP (IO ₂ ), and configurable pin / HOLD(IO ₃ ). For single-bit serial peripheral operation, the configurable pins are used as instruction/address/data input DI, data output DO, write protection/WP, and hold/HOLD. For the dual serial peripheral interface SPI, the configurable pins are used as input/output IO ₀ , input/output IO ₁ , write protection / WP, and hold / HOLD. Quaternion SPI serial peripheral interface and a peripheral interface QPI four yuan, the pin can be configured as a system for input / output IO0, input / output IO1, input / output IO2, and input / output IO _3.

Operations that do not cause bus access violations can be performed on different flash memory dies simultaneously. Many operations are initiated by inputting an instruction (an opcode with or without an address) into the serial peripheral bus and then performing a self-timed operation through control of the internal control circuit for a period of time ranging from about milliseconds to seconds. The above operations include, for example, programming/erasing the memory array, writing the status register, and programming/erasing the secure register. Since the internal operations included in the execution of the above instructions do not involve any bus access, these operations are suitable for operation in synchronization with other similar operations or other operations involving sink access. Sending Operations that still involve bus access after instructions include, for example, memory array read, status read, device recognize read, SFDP read, secure scratchpad read, cache load (NAND), and memory The initial part of the code (NOR).

A higher memory density achievable with stacking all of the same types of flash memory dies. Figure 1 shows a tandem peripheral interface flash memory device 10 comprising four stacked identical flash memory dies 11, 12, 13 and 14. The flash memory chips 11, 12, 13 and 14 are each provided with six serial peripheral interface pins, and a total of eight pins, such as a power supply (Vcc) and a ground (GND). And the flash memory dies 11, 12, 13, and 14 can include, for example, NOR, NAND, or any suitable flash memory die. In the present embodiment, stacking is performed using four flash memory dies, but the present invention is not limited thereto. In other embodiments, any number of flash memory dies may also be used for stacking.

In another embodiment of the present invention, different flash memory dies may be selected for stacking, and the flash memory device may be provided by selecting flash memory dies according to different capacities and characteristics. The capacity and characteristics to match certain applications. 2 shows a tandem peripheral interface flash memory device 20 having stacked SPI-NOR flash memory dies 21 and SPI-NAND flash memory dies 22, 23 and 24. The SPI-NOR flash memory die 21 is particularly suitable for encoding applications such as in-situ execution and code mapping, while the SPI-NAND flash memory die 22, 23 and 24 are particularly suitable for data storage. And it provides a very high density after stacking. Flash memory dies 21, 22, 23, and 24 include individual die identifiers, modified command and control logic in response to die select instructions. For faster random access memory, two SPI-NOR flash dies and two SPI-NAND flash memories Body dies are stacked or additional SPI-NOR flash memory is added. SPI-NAND flash memory dies (not shown) suitable for coded storage applications can also be substituted for SPI-NOR flash memory dies 21, for example, SPI-NAND disclosed in U.S. Patent Publication No. US 2012/0084491 Flash memory. The size of the memory array in each of the flash memory dies of the stack may be the same or different, or may be partially the same or partially different. For example, in the flash memory device 20 shown in FIG. 2, the SPI-NOR flash memory die 21 does not need to be large, and for many general XIP and code mapping, for example, 16-32 Mb is Sufficient; SPI-NAND flash memory dies can be larger, such as 1 Gb, to provide sufficient data storage for many general applications. The above capacity is only a rough description, which may increase due to the development of manufacturing technology.

Each of the flash memory chips 21, 22, 23, and 24 is configured with six serial peripheral interface pins, and a total of eight pins, such as a power supply (Vcc) and a ground (GND). And the flash memory dies 21, 22, 23, and 24 can include, for example, NOR, NAND, or any suitable flash memory die.

The tandem peripheral interface flash memory device disclosed herein may provide any combination of one or more of the following advantages, and may have other advantages: (a) multiple stacked flash memory dies are only required a single physical/CS pin; (b) an eight-pin package that implements all serial peripheral interface protocols, including a four-element serial interface protocol; (c) some serial peripheral interfaces operate synchronously; (d) only There is a need for minor modifications to the existing serial peripheral interface flash memory die design; (e) for conventional multi-chip packaging techniques; and (f) stackable heterogeneous flash memory die Achieve versatility and target performance.

The serial peripheral interface flash memory device disclosed by the present invention is constructed by using stacked flash memory die, is compatible with the conventional flash memory instruction set, and can be processed by a "die selection" command. expansion. For example, as shown in Figure 3, the die select instruction can be two byte instructions (eg, C2 hexadecimal die select opcode (hex opcode)) followed by an octet crystal Grain identifier. Wherein, although the number of bits required for the die identifier depends on the maximum number of stackable flash memory dies in the serial peripheral flash memory device, and only two digits are required, four can be specified. The stacked flash memory dies, but still retaining the octet die identifier length, so that the commanded die identifier ends at the byte boundary by convention.

The die select command selects any of the individual flash memory dies in the multi-die stack package in the following manner. The die select command and the particular die identifier of the flash die to be accessed are sent by the controller (not shown) to the serial peripheral interface flash memory device. Then, all of the stacked flash memory dies will run a die select command, wherein the flash memory die that conforms to the die identifier will be enabled in response to all serial peripheral interface instruction sets (SPI instruction). Set), while other flash memory dies are enabled to respond only to a subset of the serial peripheral interface set (here, the Universal instruction subset), but not to other Serialize the peripheral interface instruction set. To support synchronous operation, the command and control logic for the non-selected die can continue to perform any internal operations currently in progress. This feature can be designed into the command and control logic of each stacked flash memory die.

Fig. 4 and Fig. 5 are examples of the synchronous operation, and the examples here are synchronous erasing and reading. For the sake of clarity, it is omitted from the instruction sequence. A plurality of other signals commonly used during the column. The above signals include the /CS signal. For example, the /CS signal is converted to low to select the device before each instruction and is converted to high when internal erase, encode, and write status register loops are allowed. To complete the instruction. The /CS signal can be used in the method together with the die select command in the manner described above.

The sequence of instructions illustrated in FIG. 4 begins with a die select opcode DS followed by a die identifier 0 followed by an erase opcode ER (eg, a Chip Erase instruction). Die 0 performs an internal self-timed erase operation when the /CS signal transitions from low to high. The next instruction sequence is the die select opcode DS, followed by the die identifier 1, followed by the read opcode RD, the associated address bit ADR, and the redundancy bit DMY, so that the die 1 performs the read. Take the operation. The read operation is initiated when the /CS signal transitions from high to low, and is completed when the /CS signal transitions from low to high. In this example, the time of the read operation is longer than the erase operation. The next instruction sequence is the die select opcode DS, followed by the die identifier 0, followed by the read state register opcode RSR for reading the data in the state register (eg, state temporary The BUSY bit SO in the device 1 to confirm whether the erase operation has been completed. For example, when the serial peripheral interface flash memory die performs an internal erase, encode, or write state register loop, the BUSY bit is a read-only bit set to one. Here, die 0 responds through the data in the status register to indicate that the erase operation is no longer performed and that die 0 is ready to perform other operations.

The instruction sequence shown in FIG. 5 starts with the die select operation code DS, followed by the die identifier 0, followed by the erase operation code ER, so that the die 0 is executed when the /CS signal transitions from low to high. Internal self-timed erase operation. Next The instruction sequence is the die selection opcode DS, followed by the die identifier 1, followed by the read opcode RD, the associated address bit ADR, and the redundancy bit DMY, so that the die 1 performs the reading. operating. The read operation is initiated when the /CS signal transitions from high to low, and is completed when the /CS signal transitions from low to high. In this example, the read operation time is shorter than the erase operation and the read operation is completed before the erase operation is completed. The next instruction sequence is the die select opcode DS, followed by the die identifier 0, followed by the read state register opcode RSR, which is used to read the data in the state register to confirm the erase. Whether the operation is completed. At this time, although the internal erase command of the die 0 is still being executed, the die 0 becomes the selected die in response to the die select command, and responds to the data in the state register to indicate the erase operation. Still in progress. The next instruction sequence is another read status register operand RSR to reconfirm the data in the status register. At this point, die 0 is responsive through the data in the status register to indicate that the erase operation is no longer performed and that die 0 is ready to perform other operations.

Figure 6 is a flow chart showing the execution of the die selection instruction. First, a die select instruction is received (block 60). At the same time, if there is any ongoing internal self-timed operation, the operation continues (block 61). Next, it is compared whether the grain identifiers of the respective grains in the stacked grains conform to the grain identifiers following the die selection command (block 62). If the two are found to be consistent, the flash memory die is placed or retained in the full serial peripheral interface instruction set execution mode (block 64), and the full serial peripheral interface instruction set execution mode is The flash memory die can respond to the standard mode of all instructions in the entire serial interface of the serial interface. If the two are not detected, the flash memory die is placed or left in the pass. Execute the pattern with the subset of instructions (block 66). The above-mentioned general instruction subset execution mode is a new mode in which the flash memory die responds only to the general instructions. As used herein, "general purpose instructions" refers to a subset of a series of peripheral interface instruction sets that include die select instructions and certain standard instructions (e.g., device reset). Wherein, whether the flash memory die can respond to the entire serial peripheral interface instruction set, it can respond to the subset. This execution flow can be implemented in any desired method, such as a hardware, firmware, software, state machine, any combination of the above, or in any other method.

Stacked flash memory dies can perform many different types of synchronous operations. Due to the different time requirements for internal erase, program, and write operations in flash memory, having the stacked flash memory die have the ability to execute different instructions separately can advantageously increase data throughput during normal operation ( Throughput, as well as promoting efficient "code downloads" during system manufacturing. For example, synchronous operation is especially beneficial for "Read while Write" (status register write, whether 0 to 1 or 1 to 0), "read during program/erase" ( Does not include the data transfer part of the SPI-NOR programming instruction), and "multi-die programming/erasing" (excluding the data transfer part of the SPI-NOR programming instruction). Although described herein in terms of two simultaneous operations, the present invention is not limited thereto, and the number of synchronous operations may be as many as the number of stacked flash memory chips. Each stacked flash memory die can be individually enabled by a die select command and acknowledged by reading the status register, for example, the die is performing a write, program or erase operation Receive new instructions or receive new ones.

When the power is turned on, a specific die (such as a die) can be required according to requirements. The crystal whose identifier is "00" is designated as the active die. Before the general operation, the SFDP (Serial Flash Discoverable Parameters) command can be used to identify whether the serial peripheral interface flash memory device has a stacked die and supports the "die selection" function. To achieve this goal, a vendor-specific SFDP header can be attached to the primary SFDP table.

The unique die identifier can be assigned to each stacked flash memory die by any technique during the manufacturing process. For example, different die identifier bits can be provided in the scratchpad as needed, and the bits can be pre-programmed in the manufacturing process before stacking of the die. Since the scratchpad bits are small, there is no space penalty. It should be noted, however, that when stacking the dies, care must be taken that the grain identities of all of the flash memory dies in the stack are not repeated with each other and are stacked in a suitable order. Alternatively, a die ID pin (eg, a pad) may be provided on the flash memory die, and the pad is wire bonded to VCC or GND in a suitable manner to the stack. The flash memory grains establish individual unique grain identifiers. For example, when there are two flash memory dies, the die identifier of the first flash memory die can be soldered to GND to establish a first die identifier, and the second The grain identifier of the flash memory die is soldered to Vcc to create a second die identifier; when there are four flash memory die, two crystals can be provided for each flash memory die The grain identifier pin is used to solder the two-grain identifier of the first flash memory die to the GND to establish a first die identifier, and the second die of the second flash memory die is identified. The pins are wire-bonded to GND and Vcc respectively to establish a second die identifier, and the two die identifier pins of the third flash memory die are respectively wire-bonded to Vcc and GND to establish a third die identification. Symbol and will be the fourth flash memory crystal The two-grain identifier of the grain is wire-bonded to Vcc to create a fourth grain identifier. When a die identifier register bit is provided, the die identifier pin can be used as a logic input through an individual transmit gate input to the die identifier register bit. Although the die identifier pin can cause space penalties (especially when it is a pad), advantageously, the risk of incorrectly specifying the die identifier in this way is low.

While stacked flash memory dies may be placed in packages of more than eight pins, and the techniques disclosed herein may be combined with other additional pins, the techniques disclosed herein may advantageously be The stacked flash memory die can be used in an 8-pin package that is simple and has a very small footprint. Eight-pin packages (such as Small Outline Intefrated Circuit (SOIC) and WSON (Very Very Thin Small Outline No Lead)) are still widely used because the layout of the system printed circuit board is only a small area. For tandem flash memory devices.

FIG. 7 is a side view schematically showing an eight-pin WSON type serial peripheral interface flash memory device 70 including two stacked flash memory chips 72 and 74 in a package body 71. Although any suitable stacking technique can be used, the tandem peripheral interface flash memory device of the present embodiment is illustratively using a spacer body 73 to ensure the bottom of the flash memory die 72 and flash memory. There is sufficient space between the leads on the top of the bulk die 74 and the corresponding wire bonds (e.g., leads 83, 84 and corresponding bond wires). The spacer 73 can be of any suitable type, such as a solid, thick adhesive viscous adhesive or other adhesive material having a top and bottom adhesive surface. The flash memory die 74 is attached to the thermal pad 76 using any suitable technique, such as sticking Primer 75 or other adhesive material. The flash memory cells 72 and 74 are wire bonded to a plurality of wires of a lead frame (e.g., through leads 81, 82, 83, 84 and corresponding bonding wires). The plurality of wires of the leadframe are exposed outside of the package body 71 (such as regions 77 and 78) to provide pad connections to external circuitry.

FIG. 8 is a side view schematically showing an eight-pin WSON type serial peripheral interface flash memory device 90 including two stacked flash memory chips 92 and 94 in a package body 91. The serial peripheral interface flash memory device 90 uses stacking offset techniques to avoid leads between the bottom of the flash memory die 92 and the top of the flash memory die 94 and corresponding bond wires (eg, leads 99 and corresponding Interference between the wire bonds). The flash memory dies 92 and 94 are secured to the stack by any suitable material 93, such as a solid or adhesive having a top and bottom adhesive surface. The flash memory die 94 is attached to the thermal pad 96 using any suitable technique, such as adhesive 95 or other adhesive material. The flash memory die 92 and 94 are wire bonded to the plurality of wires of the leadframe (e.g., through leads 98, 99 and corresponding bond wires). The plurality of wires of the leadframe are exposed outside of the package body 91 (e.g., region 97) to provide pad connections to external circuitry.

FIG. 9 is a side view schematically showing an eight-pin WSON type serial peripheral interface flash memory device 100 including two stacked flash memory chips 102 and 104 in a package body 101. Although any suitable stacking technique can be used, the tandem peripheral interface flash memory device 100 of the present embodiment uses different sized or shaped dies to avoid the bottom of the flash memory die 102 and flash memory crystals. Interference between the leads of the top of the pellets 104 and the corresponding bond wires (e.g., leads 113, 114 and corresponding bond wires). Flash memory The dies 102 and 104 are secured to the stack by any suitable material 103, such as a solid or adhesive having a top and bottom adhesive surface. The flash memory die 104 is attached to the thermal pad 106 using any suitable technique, such as an adhesive 105 or other adhesive material. The flash memory die 102 and 104 are wire bonded to the plurality of wires of the leadframe (e.g., through leads 111, 112, 113, 114 and corresponding bond wires). The plurality of wires of the leadframe are exposed outside of the package body 101 (such as regions 107 and 108) to provide pad connections to external circuitry.

The stacking techniques and other stacking techniques described in this disclosure are not necessarily mutually exclusive, and two or more of the above techniques can be used in the fabrication of any particular stack. A number of different stacking techniques have been disclosed in the prior art, for example, see U.S. Patent Publication No. US 2011/0195529. Although Figures 7-9 are illustrated by wire bonding, any other soldering technique (e.g., via) suitable for use between the die and the package pins may be used in place of or in combination with wire bonding.

The embodiments disclosed in the present specification are intended to be illustrative of the scope of the present invention, and are not intended to limit the scope of the invention, and the scope of the invention is defined by the scope of the appended claims. Modifications and variations of the embodiments disclosed in the present invention are possible, and those skilled in the art can read the present invention to actually replace the items described in the embodiments. Moreover, the specific values recited herein are merely exemplary and may vary as desired. Other variations and modifications of the disclosed embodiments of the invention may be made without departing from the spirit and scope of the invention, and the scope of the invention is limited by the scope of the appended claims. Defined.

10‧‧‧Sequenced peripheral interface flash memory device

11, 12, 13, 14‧‧‧ series of peripheral interface flash memory grains

Claims (13)

The flash memory device includes: a first serial peripheral interface ("SPI") flash memory die having a first die identifier and a first serial peripheral interface pin set; a second Aligning the peripheral interface flash memory die, having a second die identifier and a second serial peripheral interface pin set; and a package having the first serial peripheral interface arranged in a stacked configuration a flash memory die and the second serial peripheral interface flash memory die, and a series of peripheral interface package pin groups; wherein the serial peripheral interface package pin groups are respectively coupled to the above The first series of peripheral interface pin sets and the second series of peripheral interface pin sets. The flash memory device of claim 1, wherein: the first serial peripheral interface flash memory die includes a first command and control logic for connecting the first die according to the connection a die select command of the identifier to enable the first serial peripheral interface flash memory die to respond to a series of peripheral interface command sets, and according to the die select command not having the first die identifier So that the first serial peripheral interface flash memory die only responds to one of the general command subsets of the serial peripheral interface command set; and the second serial peripheral interface flash memory die includes a second command And the control logic, configured to enable the second serial peripheral interface flash memory die to respond to the serial peripheral interface instruction set according to the die selection instruction following the second die identifier, and according to the unconnected Have the second The die select command of the die identifier enables the second serial peripheral interface flash memory die to only respond to the general command subset of the serial peripheral interface command set. The flash memory device of claim 2, further comprising: a plurality of first register bits located on the first serial peripheral interface flash memory die for storing the first a first identifier and control logic coupled to the first register bit; and a plurality of second register bits located on the second serial peripheral interface flash memory die The second die identifier is stored, and the second command and control logic are coupled to the second register bit. The flash memory device of claim 1, wherein: the first serial peripheral interface pin group includes a first chip select pin, a first timing pin, and four a configurable pin; the second serial peripheral interface pin set includes a second chip select pin, a second timing pin, and four second configurable pins; and the serial peripheral interface package The pin group includes a third chip select pin coupled to the first chip select pin and the second chip select pin, coupled to the first timing pin and the second timing pin A third timing pin is coupled to the four first configurable pins and the four third configurable pins of the four second configurable pins. The flash memory device of claim 1, wherein the first serial peripheral memory flash memory die further comprises at least one first die identifier pin, the first die identification a pin system coupled to the ground to at least partially establish the first die identifier; and The second serial peripheral memory flash memory die further includes at least one second die identifier pin, and the second die identifier pin is coupled to the power source to at least partially establish the second die Identifier. The flash memory device of claim 3, wherein: the first serial peripheral interface flash memory die further comprises at least one first transfer gate and at least one first die identifier pin The first die identifier pin is coupled to the at least one of the first register bits through the first transfer gate to at least partially establish the first die identifier; and the second string The column peripheral interface flash memory die further includes at least one second transfer gate and at least one second die identifier pin, wherein the second die identifier pin is coupled to the first via the second transfer gate At least one of the two register bits to at least partially establish the second die identifier. The flash memory device of claim 6, wherein: the first die identifier pin is coupled to the ground; and the second die identifier pin is coupled to the power source. The flash memory device of claim 1, further comprising: a third serial peripheral interface flash memory die having a third die identifier and a third serial peripheral interface a fourth set of peripheral interface flash memory die having a fourth die identifier and a fourth serial peripheral interface pin set; wherein the package further has the above arrangement in the stacked configuration The third series of peripheral interface flash memory dies and the fourth series of peripheral interface flash memory dies. The flash memory device of claim 8, wherein: the first serial peripheral interface flash memory die further has two die identifier pins for coupling to ground to establish The first die identifier; the second serial peripheral flash memory die further has two die identifier pins for respectively coupling to ground and a power source to establish the second die identifier The third serial peripheral memory flash memory die further has two die identifier pins for respectively coupled to the power source and the ground to establish the third die identifier; and the fourth serial The peripheral interface flash memory die has two die identifier pins for coupling to a power source to establish the fourth die identifier. The flash memory device of claim 1, wherein: the first serial peripheral interface flash memory die comprises SPI-NOR flash memory; and the second serial peripheral interface flashes The memory die includes SPI-NOR flash memory. The flash memory device of claim 1, wherein: the first serial peripheral interface flash memory die comprises SPI-NAND flash memory; and the second serial peripheral interface flashes The memory die includes SPI-NAND flash memory. The flash memory device of claim 1, wherein: the first serial peripheral interface flash memory die comprises SPI-NOR flash memory; The second serial peripheral interface flash memory die includes SPI-NAND flash memory. A method of performing a synchronous operation, applicable to a serial peripheral interface ("SPI") flash memory device, wherein the serial peripheral interface flash memory device has a serial peripheral interface package including a chip select pin The leg set includes: receiving, by the chip selection pin of the serial peripheral interface flash memory device, a first chip selection active signal, wherein the serial peripheral interface flash memory device comprises: a first series periphery The interface flash memory die has a first die identifier and a first serial peripheral interface pin group; and a second serial peripheral interface flash memory die having a second die identification And a second serial peripheral interface pin set; the first serial peripheral interface flash memory die and the second serial peripheral interface flash memory die stack, and the first series periphery The interface pin group and the second serial peripheral interface pin group are coupled in parallel to the serial peripheral interface package pin group; and the first chip selection active signal is provided in parallel to the above a series of peripheral interface flash memory die and the second serial peripheral interface flash memory die; and the step of receiving the first chip to select an active signal, in the first serial peripheral interface flash memory Performing a first die select command on the die and the second serial peripheral interface flash memory die to enable the first serial peripheral peripheral flash memory die to respond to a series of peripheral interface command sets, And enabling the second serial peripheral interface flash memory die to ring only And a plurality of general instruction subsets of the serial interface module set, wherein the first die select command specifies a first die identifier to the serial peripheral flash memory device, and the universal command subset includes a die select command; the chip select pin of the serial peripheral interface flash memory device receives a first chip select stop signal for the first serial peripheral interface flash memory die and the second Terminating the execution of the first die select command on the serial peripheral flash memory die; when the first serial peripheral interface flash memory die is enabled to respond to the serial peripheral interface command set, The chip select pin of the serial peripheral interface flash memory device receives a second chip select active signal, and the second chip select active signal is provided in parallel to the first serial peripheral interface flash memory die and The second serial peripheral interface flash memory die; and the step of receiving the second chip to select an active signal, in the first serial peripheral interface Performing a first serial peripheral interface instruction on the flash memory die on a non-universal instruction, the first serial peripheral interface instruction causing execution of an internal self-timing operation; and the serial peripheral memory flash memory The chip select pin of the device receives a second chip select stop signal to terminate the first serial peripheral interface command on the first serial peripheral interface flash memory die, but does not terminate the internal self-timing The chip selection pin of the serial peripheral interface flash memory device receives a third chip selection active signal, and the third chip selects an active signal. The number is provided in parallel to the first serial peripheral interface flash memory die and the second serial peripheral interface flash memory die; and the step of receiving the third chip to select the active signal, in the first string Performing a second die selection command on the column peripheral interface flash memory die and the second serial peripheral interface flash memory die, so that the second serial peripheral interface flash memory die response is Aligning the peripheral interface instruction set and enabling the first serial peripheral interface flash memory die to respond only to the general command subset, wherein the second die select command assigns a second die identifier to the Aligning the peripheral flash memory device; the chip select pin of the serial peripheral interface flash memory device receives a third chip select stop signal for the first serial peripheral interface flash memory die And performing the execution of the second die selection command on the second serial peripheral interface flash memory die; when the second serial peripheral interface flash memory die is enabled When the peripheral interface instruction set is serialized, the fourth chip selection active signal is received by the chip selection pin of the serial peripheral interface flash memory device, and the fourth chip selection active signal is provided in parallel to the first Aligning the peripheral interface flash memory die and the second serial peripheral interface flash memory die; combining the step of receiving the fourth chip to select the active signal, and flashing the memory on the second serial peripheral interface Performing a second serial peripheral interface command on the granule and performing the internal self-timing operation on the first serial peripheral interface flash memory die; and the above-mentioned serial peripheral interface flash memory device Chip select pin A fourth wafer selection stop signal is received to terminate the second serial peripheral interface command.