kopia lustrzana https://github.com/oddwires/RP2040-code
38 wiersze
2.4 KiB
Plaintext
38 wiersze
2.4 KiB
Plaintext
.program pio_DAC
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; Repeatedly get one word of data from the TX FIFO, stalling when the FIFO is
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; empty. Write the data to the OUT pin group.
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.wrap_target
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; Get data bits from DMA via Output Shift Register (OSR) to PINS.
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out PINS, 8 ; 1 machine cycle
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; ============================
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;.pseudo_wrap Fast loop = 1 machine cycle ; Frequencies >= 34Hz are configured to wrap at this point
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; ============================
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set x,1 ; 1 machine cycle
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loop01: ; Loop will run 2 times
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nop [29] ; 30 machine cycles
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jmp x-- loop01 ; 1 machine cycle Bump x and Jump
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; ==============================
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; Slow loop = 64 machine cycles
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; ==============================
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; Frequencies < 34Hz are configured to wrap at this point
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.wrap
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% c-sdk {
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// This is a raw helper function for use by the user which sets up the GPIO output, and configures the SM
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// to output on a particular pin.
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// Note: 1) No divider is specified for the SM, so it will default to the same speed as the CPU.
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// 2) Hard coded to use 8 bit DAC hardware
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void pio_DAC_program_init(PIO pio, uint sm, uint offset, uint start_pin) {
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for (uint i=start_pin; i<(start_pin+8); i++) { pio_gpio_init(pio, i); } // Allow PIO to control GPIO pins as outputs
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pio_sm_set_consecutive_pindirs(pio, sm, start_pin, 8, true); // Set the pin direction to output (in PIO)
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pio_sm_config c = pio_DAC_program_get_default_config(offset); // Define PIO Configuration structure
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sm_config_set_out_pins(&c, start_pin, 8); // Configure pins to be targeted by the OUT (and MOV) commands
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sm_config_set_out_shift(&c, true, true, 8); // Shift right, Autopull enabled, 6/8 bits
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sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX); // Set TX_FIFO to 8. Improves stability at high frequencies
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pio_sm_init(pio, sm, offset, &c); // Load configuration and jump to start of the program
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pio_sm_set_enabled(pio, sm, true);
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}
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%} |