Fix spi bug

Was reading a value from x, shifting it, but then not writing it back. This caused an infinite loop as it would never move on from the MSB.
2022-03-10 11:16:35 -06:00
parent 6f3155cf35
commit ee5271d955
1 changed files with 2 additions and 17 deletions
--- a/sw/spi.s
+++ b/sw/spi.s
@@ -26,24 +26,9 @@ _spi_write_byte:
        adc #$01
        sta BB_SPI_BASE     ; Write clock
        txa
-        lsr                 ; Select net bit
+        lsr                 ; Select next bit
+        tax
        bne @loop           ; Stop when mask is 0
        ply                 ; Restore regs
        plx
        rts                 ; Return
-
-
-
-
-    and #$01            ; Get first bit
-    asl
-    asl
-    sta BB_SPI_BASE     ; write bit without clock
-    adc #$01            
-    sta BB_SPI_BASE     ; write bit with clock
-    tay
-    and #$022
-
-    ply
-    plx
-    rts