README.md

RP2040-HAT-C_SPI_TEST

test for using pio for spi interface with w5500 chip.

Test Case 1

.program wiznet_spi_write_read
.side_set 1

public write_bits:
    out pins, 1             side 0
    jmp x-- write_bits      side 1
    set pins 0              side 0
public write_end:
read_byte_delay:
    set pindirs 0           side 0 [1] 
read_byte:
    set x 6                 side 1
read_bits:
    in pins, 1              side 0
    jmp x-- read_bits       side 1
    in pins, 1              side 0
    jmp y-- read_byte_delay side 0
public read_end:

Run Loopback code (clock 16.6MHz)

Test Case 2

.program wiznet_spi_write_read
.side_set 1

public write_bits:
    out pins, 1             side 0
    jmp x-- write_bits      side 1
    set pins 0              side 0
public write_end:
read_byte_delay:
    set pindirs 0           side 0 
read_byte:
    set x 6                 side 1
read_bits:
    in pins, 1              side 0
    jmp x-- read_bits       side 1
    in pins, 1              side 0
    jmp y-- read_byte_delay side 0
public read_end:

Run Loopback code (clock 16.6MHz)

Test Case 3

.program wiznet_spi_write_read
.side_set 1

public write_bits:
    out pins, 1             side 0
    jmp x-- write_bits      side 1
    set pins 0              side 0
public write_end:
read_byte_delay:
    set pindirs 0           side 0
read_byte:
    set x 6                 side 1
read_bits:
    in pins, 1              side 0
    jmp x-- read_bits       side 1
    in pins, 1              side 0
    jmp y-- read_byte       side 0
public read_end:

Run Loopback code (clock 16.6MHz)