diff options
Diffstat (limited to 'src/uart_rx.pio')
| -rw-r--r-- | src/uart_rx.pio | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/uart_rx.pio b/src/uart_rx.pio new file mode 100644 index 0000000..a903176 --- /dev/null +++ b/src/uart_rx.pio @@ -0,0 +1,22 @@ +.program uart_rx + +.wrap_target +start: + wait 0 pin, 0 [6] ; wait for START bit + + set x, 7 [4] ; read 8 DATA bits and offset + ; clock for better readings +bitloop: + in pins, 1 + jmp x--, bitloop [6] + + jmp pin, outb ; got STOP bit, output byte + +error: + irq wait 0 ; no STOP bit, + wait 1 pin, 0 ; set err IRQ and await reset + jmp start + +outb: + push block +.wrap |