Move devices into devices folder

2022-04-16 21:47:54 -05:00
parent c5f1b64cba
commit 238a4b6f98
17 changed files with 10 additions and 9 deletions
--- a/sw/devices/uart.s
+++ b/sw/devices/uart.s
@@ -0,0 +1,36 @@
+.include "io.inc65"
+
+.importzp sp, sreg
+
+.export _uart_txb, _uart_txb_block
+.export _uart_rxb
+.export _uart_status
+
+.autoimport	on
+
+.code
+
+; @in A: byte to transmit
+; Transmits a byte over the UART
+_uart_txb:
+        sta UART_TXB        ; Just write value, don't wait
+        rts
+
+_uart_txb_block:
+        pha
+        sta UART_TXB        ; Write value
+@1:     lda UART_STATUS     ; Wait for status[0] to be 0
+        bit #$01
+        bne @1
+        pla
+        rts
+
+_uart_rxb:
+        lda UART_RXB        ; Read value
+        ldx #$00
+        rts
+
+_uart_status:
+        lda UART_STATUS
+        ldx #$00
+        rts