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The UART_TX program, and my similar program, fail.
Single OUT pin and single SIDE pin mapped to same GPIO.
GPIO does not change with out pins, 1 but stays at the last SIDE setting.
In the UART program, the stop and start bits are output, but no data.
Setting the SIDE pin to a different GPIO sees the data on the OUT GPIO and the stop/start bits on the SIDE GPIO.
.program uart_tx
.side_set 1 opt
; An 8n1 UART transmit program.
; OUT pin 0 and side-set pin 0 are both mapped to UART TX pin.
pull side 1 [7] ; Assert stop bit, or stall with line in idle state
set x, 7 side 0 [7] ; Preload bit counter, assert start bit for 8 clocks
bitloop: ; This loop will run 8 times (8n1 UART)
out pins, 1 ; Shift 1 bit from OSR to the first OUT pin
jmp x-- bitloop [6] ; Each loop iteration is 8 cycles.
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