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Uart pio fix zeros

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Prevent UART from only getting 0s from the output
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Michael van Niekerk 2023-07-30 22:13:27 +02:00 committed by GitHub
parent 39c1cc9f00
commit 56b21ad429
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 6 additions and 4 deletions
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10
examples/rp/src/bin/pio_uart.rs
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@ -338,7 +338,7 @@ mod uart_rx {
start: start:
wait 0 pin 0 ; Stall until start bit is asserted wait 0 pin 0 ; Stall until start bit is asserted
set x, 7 [10] ; Preload bit counter, then delay until halfway through set x, 7 [10] ; Preload bit counter, then delay until halfway through
rx_bitloop: ; the first data bit (12 cycles incl wait, set). rx_bitloop: ; the first data bit (12 cycles incl wait, set).
in pins, 1 ; Shift data bit into ISR in pins, 1 ; Shift data bit into ISR
jmp x-- rx_bitloop [6] ; Loop 8 times, each loop iteration is 8 cycles jmp x-- rx_bitloop [6] ; Loop 8 times, each loop iteration is 8 cycles
jmp pin good_rx_stop ; Check stop bit (should be high) jmp pin good_rx_stop ; Check stop bit (should be high)
@ -347,7 +347,8 @@ mod uart_rx {
wait 1 pin 0 ; and wait for line to return to idle state. wait 1 pin 0 ; and wait for line to return to idle state.
jmp start ; Don't push data if we didn't see good framing. jmp start ; Don't push data if we didn't see good framing.
good_rx_stop: ; No delay before returning to start; a little slack is good_rx_stop: ; No delay before returning to start; a little slack is
in null 24
push ; important in case the TX clock is slightly too fast. push ; important in case the TX clock is slightly too fast.
"# "#
); );
@ -361,8 +362,9 @@ mod uart_rx {
sm_rx.set_pin_dirs(Direction::In, &[&rx_pin]); sm_rx.set_pin_dirs(Direction::In, &[&rx_pin]);
cfg.clock_divider = (U56F8!(125_000_000) / (8 * baud)).to_fixed(); cfg.clock_divider = (U56F8!(125_000_000) / (8 * baud)).to_fixed();
cfg.shift_out.auto_fill = false; cfg.shift_in.auto_fill = false;
cfg.shift_out.direction = ShiftDirection::Right; cfg.shift_in.direction = ShiftDirection::Right;
cfg.shift_in.threshold = 32;
cfg.fifo_join = FifoJoin::RxOnly; cfg.fifo_join = FifoJoin::RxOnly;
sm_rx.set_config(&cfg); sm_rx.set_config(&cfg);
sm_rx.set_enable(true); sm_rx.set_enable(true);