ceda2vga/src/main.c

96 lines
2.0 KiB
C

/**
* @file main.c
* @author giomba@glgprograms.it
* @brief
*
* @copyright Copyright Retrofficina GLG Programs (c) 2022
*
*/
#include "hardware/clocks.h"
#include "hardware/pio.h"
#include "hardware/pll.h"
#include "hardware/structs/pio.h"
#include "pico/stdlib.h"
#include <stdint.h>
#include "vga.pio.h"
#include <stdio.h>
#define FRAMES 2
#define HPIXEL 640
#define VPIXEL 480
#define BPP 1
typedef struct Frame
{
uint8_t data[HPIXEL * VPIXEL * BPP / 8];
} Frame;
static Frame frames[FRAMES] = {0};
static void vga_program_init(PIO pio, uint sm, uint offset)
{
// magic definition of the called function?
pio_sm_config c = vga_free_run_program_get_default_config(offset);
sm_config_set_out_pins(&c, 22, 1);
pio_gpio_init(pio, 22);
pio_sm_set_consecutive_pindirs(pio, sm, 22, 1, true);
pio_sm_init(pio, sm, offset, &c);
pio_sm_set_clkdiv_int_frac(pio, sm, 1, 0);
pio->sm->shiftctrl = (1 << PIO_SM0_SHIFTCTRL_FJOIN_TX_LSB) |
(1 << PIO_SM0_SHIFTCTRL_OUT_SHIFTDIR_LSB) |
(1 << PIO_SM0_SHIFTCTRL_OUT_SHIFTDIR_LSB) |
(1 << PIO_SM0_SHIFTCTRL_AUTOPULL_LSB);
pio_sm_set_enabled(pio, sm, true);
}
int main()
{
// main clock = VCO / divider1 / divider2 = 126MHz
pll_init(pll_sys, 1, 1500 * MHZ, 6, 2);
stdio_init_all();
#if 0
const uint LED_PIN = PICO_DEFAULT_LED_PIN;
gpio_init(LED_PIN);
gpio_set_dir(LED_PIN, GPIO_OUT);
#endif
// "draw" an horizontal dotted line (?)
for (unsigned int c = 0; c < 20; c += 3)
{
frames[0].data[80 * 64 + 20 + c] = 0x55;
}
for (unsigned int c = 0; c < 20; c += 3)
{
frames[0].data[80 * 128 + 20 + c] = 0x99;
}
PIO pio = pio0;
uint offset = pio_add_program(pio, &vga_free_run_program);
uint sm = pio_claim_unused_sm(pio, true);
vga_program_init(pio, sm, offset);
printf("Welcome.\n");
while (true)
{
for (size_t i = 0; i < sizeof(frames[0].data); ++i)
{
pio_sm_put_blocking(pio, sm, frames[0].data[i]);
}
printf(".");
sleep_ms(1000);
}
}