fix spi init

system/spi.s65

@@ -10,30 +10,148 @@
 
 .ifndef INCLUDE_SPI
 INCLUDE_SPI = 1
+.scope spi_p
 
 
+.zeropage
+code_page:          .res 2  ; SPI_CODE_START + pages_written * 256
 .bss
-SPI_PAGES_WRITTEN:  .res 1
+bytes_written:      .res 1
-SPI_BYTES_WRITTEN:  .res 1
+pages_written:      .res 1
+
+.include "util/math.s65"
+; spi-transferred code will be placed here
 .segment "SPI"
-SPI_CODE_START:     ; .res $1000
+SPI_CODE_START:
-    lda $1000
+    lda '$'
-    sta $1000
+    jsr lcd_char
-    lda $1000
+    lda #<TEST_FMT
-    sta $1000
+    sta ARG0
-    lda $1000
+    lda #>TEST_FMT
-    sta $1000
+    sta ARG1
+    lda #<TEST_OUT
+    sta ARG2
+    lda #>TEST_OUT
+    sta ARG3
+    lda #$a9
+    sta ARG4
+    lda #$3c
+    sta ARG5
+    lda #$10
+    sta ARG6
+    jsr strf
+    Print TEST_OUT
+@spiloop:
     lda IO1 + IO::RA
-    lda IO1 + IO::RA
+    lda IO2 + IO::RA
-    bra SPI_CODE_START
+    nop
-    ; jsr lcd_clear
+    bra @spiloop
-    ; PrintSlow msg,20
+    jmp home
-    ; jmp home
+
-; msg:
+; TODO allocate zp memory
-    ; .asciiz "YO DAS WAR    SPI"
+fmt_idx = $30
+out_idx = $31
+;********************************************************************************
+; @function Format a string
+; @details
+;   If there is no value to be read, the Pz will be set
+;   Formats:
+;   - u: unsigned decimal integer (1 byte)
+;   - U: unsigned decimal integer (2 bytes)
+; @param ARG0-1: Format string address
+; @param ARG2-3: Output string address
+; @param ARG4+:  Additional parameters
+; @returns 
+; @modifies: A, Y
+;********************************************************************************
+.proc strf
+    stz out_idx
+    stz fmt_idx
+    ldy #0  ; position in string
+    ldx #0  ; index of format args
+@loop:
+    ldy fmt_idx
+    lda (ARG0),y
+    beq @null
+    cmp #'%'
+    beq @percent
+@normal_char:  ; store A in output string
+        ldy out_idx
+        sta (ARG2),y
+        inc fmt_idx
+        inc out_idx
+        beq @out_overflow
+        bra @loop
+@percent:  ; check for format in next position
+        iny
+        sty fmt_idx
+        lda (ARG0),y
+        beq @null
+        ; formats
+        cmp #'x'
+        beq @format_hex1
+        bra @normal_char
+@format_hex1:   ; 1 byte hex -> 2 chars
+            lda ARG4,x
+            phx
+            jsr int8_to_hex_str
+            ldy out_idx
+            sta (ARG2),y  ; most sig digit
+            iny
+            beq @out_overflow
+            txa
+            sta (ARG2),y  ; least sig digit
+            iny
+            beq @out_overflow
+            sty out_idx
+            plx
+            inx  ; 1 byte of args handeled
+            ; bra @format_return
+@format_return:  ; increment fmt_idx to swallow the formating char
+        inc fmt_idx
+        bra @loop
+@out_overflow:  ; store 0 in last position
+    ldy #$ff
+    sty out_idx
+@store_null:
+    lda #0
+@null:  ; store and return
+    ldy out_idx
+    sta (ARG2),y
+@rts:
+    rts
+.endproc
 
 
+;********************************************************************************
+; @function Convert a 1 byte number into two hex characters
+; @param A: Number to convert
+; @returns A: Most significant digit
+; @returns X: Least significant digit
+; @modifies X,Y,A
+;********************************************************************************
+.proc int8_to_hex_str
+    pha
+    and #%00001111
+    tay
+    ldx HEX_CHARS,y
+    pla
+    div A,16
+    and #%00001111
+    tay
+    lda HEX_CHARS,y
+    rts
+.endproc
+    
+    
 
+
+HEX_CHARS: .byte "0123456789ABCDEF"
+
+TEST_FMT: .asciiz "%x -> %x -> %x:)"
+TEST_OUT: .asciiz "TESTOUT"
+
+; SPI_P = as peripheral
 .code
 .struct SPI_P_Pins
     ; VIA addresses
@@ -50,12 +168,20 @@ SPI_CODE_START:     ; .res $1000
 .endstruct
 
 ;********************************************************************************
-; @function Initialize the IO Adapter for SPI
+; @function Begin listening for SPI transfers
-; @param ARG0-1 Address of the SPI_Pins struct
+; @details
+;   - initialize variables
+;   - configure shift register to shift in under external clock
+;   - enable shift register interrupts 
 ;********************************************************************************
-.proc spi_p_init
+.proc begin
-    stz SPI_PAGES_WRITTEN
+    stz pages_written
-    stz SPI_BYTES_WRITTEN
+    stz bytes_written
+    ; store address in zp
+    lda #<SPI_CODE_START
+    sta code_page
+    lda #>SPI_CODE_START
+    sta code_page + 1
     ; todo USE MASKS
     ; set Shift register to shift in under external clock on CB1
     lda #IO::ACR::SR_SIN_PHIE
@@ -64,21 +190,49 @@ SPI_CODE_START:     ; .res $1000
     ; enable SR interrupts
     lda #(IO::IRQ::IRQ | IO::IRQ::SR)
     sta SPI_IO + IO::IER
-    DEBUG_LED_ON 1
+
+    ; load SR to reset
+    lda SPI_IO + IO::SR
     rts
 .endproc
 
-.proc spi_p_read
+;********************************************************************************
-    DEBUG_LED_ON 0
+; @function Stop listening for SPI transfers
-    ; print received byte
+; @details
+;  Disables shift register interrupts
+;********************************************************************************
+.proc end
+    ; disable SR interrupts
+    lda #IO::IRQ::SR
+    sta SPI_IO + IO::IER
+    rts
+.endproc
+    
+
+
+;********************************************************************************
+; @function Read a byte from SPI
+; @details
+;  Reads a byte from the shift register and stores it in the SPI code buffer
+;********************************************************************************
+.proc read
+    ldx bytes_written
     lda SPI_IO + IO::SR
     sta SPI_CODE_START,x
-    inc SPI_BYTES_WRITTEN
+    inc bytes_written
-    jsr lcd_char
+    beq @new_page
+    rts
+@new_page:
+    inc pages_written
+    inc code_page + 1
     rts
 .endproc
 
     
+;********************************************************************************
+; @function Initialize the IO Adapter for SPI
+; @param ARG0-1 Address of the SPI_Pins struct
+;********************************************************************************
 ;********************************************************************************
 ; @function Read bytes
 ; @param X Number of bytes to send
@@ -96,8 +250,8 @@ SPI_CODE_START:     ; .res $1000
 .proc send_data
 .endproc
 
+.endscope
+
     
 
-_send_byte:
-    
 .endif