cc65 · mrdudz · Feb 28, 2016 · Jul 24, 2022 · Jul 24, 2022 · Jul 24, 2022
diff --git a/libsrc/c64/ser/c64-ssurfer.s b/libsrc/c64/ser/c64-ssurfer.s
@@ -0,0 +1,327 @@
+
+;----------------------------------------------------------------------------------------------
+; silver surfer polling mode driver for cc65
+; - work from here to create a full featured driver with interupts.
+; gpz fixed 20020828: fatal bug fixed in _ss232_params
+;----------------------------------------------------------------------------------------------
+
+                .export _rs232_init
+                .export _rs232_done
+                .export _rs232_params
+                .export _rs232_put
+                .export _rs232_get
+
+                .importzp ptr1, ptr2
+                .import   popa, popax
+
+;----------------------------------------------------------------------------------------------
+; Error codes. Beware: The codes must match the codes in the C header file
+
+ErrNotInitialized       = $01
+ErrBaudTooFast          = $02
+ErrBaudNotAvail         = $03
+ErrNoData               = $04
+ErrOverflow             = $05
+
+;; this driver should work with minor modifications
+;; with the UART in IDE-64
+
+rs16550base             = $de08
+
+fifo_rxd     = rs16550base+$00 ;8  (r)
+fifo_txd     = rs16550base+$00 ;8 (w)
+
+fifo_dll     = rs16550base+$00 ;8 (r/w)
+fifo_dlm     = rs16550base+$01 ;9 (r/w)
+
+fifo_ier     = rs16550base+$01 ;9
+
+fifo_fcr     = rs16550base+$02 ;a (w)
+fifo_iir     = rs16550base+$02 ;a (r)
+fifo_lcr     = rs16550base+$03 ;b
+fifo_mcr     = rs16550base+$04 ;c
+fifo_lsr     = rs16550base+$05 ;d
+fifo_msr     = rs16550base+$06 ;e (r)
+fifo_scratch = rs16550base+$07 ;f (r/w)
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_init (char hacked);
+;/* Initialize the serial port, install the interrupt handler. The parameter
+; * has no effect for now and should be set to 0.
+; */
+;----------------------------------------------------------------------------------------------
+
+        .code
+
+_rs232_init:
+
+        ; enable ssurfer-port
+        lda $de01
+        ora #$01
+        sta $de01
+
+        ; disable nmi's from ssurfer
+        lda #%00000000
+        sta fifo_ier
+
+        ; activate dtr
+        lda #%00000001
+        sta fifo_mcr
+
+        lda #$00       ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_done (void);
+;/* Close the port, deinstall the interrupt hander. You MUST call this function
+; * before terminating the program, otherwise the machine may crash later. If
+; * in doubt, install an exit handler using atexit(). The function will do
+; * nothing, if it was already called.
+; */
+;----------------------------------------------------------------------------------------------
+
+_rs232_done:
+        ; disable nmi's from ssurfer
+        lda #%00000000
+        sta fifo_ier
+
+        ; deactivate dtr
+        sta fifo_mcr
+
+        ; disable ssurfer-port
+        lda $de01
+        and #$fe
+        sta $de01
+
+        lda #$00       ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_params (unsigned char params, unsigned char parity);
+;/* Set the port parameters. Use a combination of the #defined values above. */
+;----------------------------------------------------------------------------------------------
+
+        .data
+
+_rs232_baudrates:
+
+        .word          (7372800 / (      50 * 16))
+        .word          (7372800 / (     110 * 16))
+        .word          (7372800 / (     269 *  8))
+        .word          (7372800 / (     300 * 16))
+        .word          (7372800 / (     600 * 16))
+        .word          (7372800 / (    1200 * 16))
+        .word          (7372800 / (    2400 * 16))
+        .word          (7372800 / (    4800 * 16))
+        .word          (7372800 / (    9600 * 16))
+        .word          (7372800 / (   19200 * 16))
+        .word          (7372800 / (   38400 * 16))
+        .word          (7372800 / (   57600 * 16))
+        .word          (7372800 / (  115200 * 16))
+        .word          (7372800 / (  230400 * 16))
+
+        .bss
+
+_rs232_tmp1:
+        .res 1
+
+        .code
+
+_rs232_params:
+
+        sta _rs232_tmp1 ; save parity
+
+        ; reset fifo
+        lda #%10000111
+        sta fifo_fcr
+
+   ; that delay thing really needed ?!
+   ; (original datasheet mentions a delay here)
+   ;      ldy #$00
+   ;      dey
+   ;      bny *-1
+
+        ; set dlab
+        lda #%10000011 ; we assmume 8n1
+        sta fifo_lcr
+
+        jsr popa
+        tay             ; save param
+
+        ; set baudrate
+        clc
+        lsr a
+        lsr a
+        lsr a
+        lsr a
+        asl a
+        tax
+        lda _rs232_baudrates,x
+        sta fifo_dll
+        lda _rs232_baudrates+1,x
+        sta fifo_dlm
+
+        tya             ; param
+        and #$0f
+        ora _rs232_tmp1 ; parity
+
+        ; reset dlab
+        sta fifo_lcr
+
+        lda #$00       ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+; check if byte available, returns AKKU=0 if none
+
+rs_getlsr:
+        lda fifo_lsr
+        and #$01
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_get (char* b);
+;/* Get a character from the serial port. If no characters are available, the
+; * function will return RS_ERR_NO_DATA, so this is not a fatal error.
+; */
+;----------------------------------------------------------------------------------------------
+; get byte (non blocking, returns byte in A or CARRY=1 - error)
+
+_rs232_get:
+        sta ptr1
+        stx ptr1+1
+
+        jsr rs_getlsr  ; check if byte available
+;         bne sk32 ; yes
+        bne sk33 ; yes
+
+        ; activate rts
+        lda #%00000011
+        sta fifo_mcr
+sk32:
+
+         ; deactivate rts
+;         lda #%00000001
+;         sta fifo_mcr
+
+        jsr rs_getlsr  ; check if byte available
+        bne sk33 ; yes
+
+        ; deactivate rts
+        lda #%00000001
+        sta fifo_mcr
+
+        lda #ErrNoData      ; no data
+        ldx #0
+        rts
+sk33:
+        ; deactivate rts
+        lda #%00000001
+        sta fifo_mcr
+
+        ; get byte
+        ldy #$00
+        lda fifo_rxd
+        sta (ptr1),y
+
+        lda #0      ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_put (char b);
+;/* Send a character via the serial port. There is a transmit buffer, but
+; * transmitting is not done via interrupt. The function returns
+; * RS_ERR_OVERFLOW if there is no space left in the transmit buffer.
+; */
+;----------------------------------------------------------------------------------------------
+
+_rs232_put:
+        tax
+        ; transmit buf ready?
+        lda fifo_lsr
+        and #%00100000
+        bne @sk1
+@sk2:
+        lda #ErrOverflow       ; overflow
+        ldx #$00
+        rts
+@sk1:
+        ; reciever ready?
+        lda fifo_msr
+        and #%00010000
+        beq @sk2
+
+        stx fifo_txd
+
+        lda #$00               ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_pause (void);
+;/* Assert flow control and disable interrupts. */
+;----------------------------------------------------------------------------------------------
+
+_rs232_pause:
+        ; activate rts
+        lda #%00000011
+        sta fifo_mcr
+
+        lda #$00       ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_unpause (void);
+;/* Re-enable interrupts and release flow control */
+;----------------------------------------------------------------------------------------------
+
+_rs232_unpause:
+        ; deactivate rts
+        lda #%00000001
+        sta fifo_mcr
+
+        lda #$00       ; ok
+        tax
+        rts
+
+;----------------------------------------------------------------------------------------------
+;unsigned char __fastcall__ rs232_status (unsigned char* status,
+;                                         unsigned char* errors);
+;/* Return the serial port status. */
+;----------------------------------------------------------------------------------------------
+
+_rs232_status:
+        sta     ptr2
+        stx     ptr2+1
+        jsr     popax
+        sta     ptr1
+        stx     ptr1+1
+
+        ldy     #$00
+
+        ; Get status
+        lda     fifo_iir
+        and     #%00000001
+        sta     _rs232_tmp1
+        lda     fifo_msr
+        lsr     a
+        and     #%01010000
+        ora     _rs232_tmp1
+        sta     _rs232_tmp1
+        lda     fifo_lsr
+        and     #%00101110
+        ora     _rs232_tmp1
+        sta     (ptr1),y
+
+        ; Get errors
+        lda     #$00    ; ok
+        sta     (ptr2),y
+
+        lda     #$00    ; ok
+        tax
+        rts