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Move clock setup into VGA module.

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This commit is contained in:
giomba 2022-12-03 20:59:49 +01:00
parent 36cc3e1c0a
commit 5f11fa209f
2 changed files with 30 additions and 28 deletions
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28
src/main.c
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@ -7,9 +7,6 @@
*
*/
#include "hardware/clocks.h"
#include "hardware/pll.h"
#include "pico/stdlib.h"
#include <stdint.h>
@ -21,33 +18,8 @@
#include "framebuffer.h"
#include "vga.h"
void setup_clocks(void)
{
// disable resuscitation clock
clocks_hw->resus.ctrl = 0;
// before changing PLL, switch sys and ref cleanly away from their aux sources
hw_clear_bits(&clocks_hw->clk[clk_sys].ctrl, CLOCKS_CLK_SYS_CTRL_SRC_BITS);
while (clocks_hw->clk[clk_sys].selected != 0x1)
tight_loop_contents();
hw_clear_bits(&clocks_hw->clk[clk_ref].ctrl, CLOCKS_CLK_REF_CTRL_SRC_BITS);
while (clocks_hw->clk[clk_ref].selected != 0x1)
tight_loop_contents();
// set PLL at 126 MHz, and wait for it to stabilize
pll_init(pll_sys, 1, 1512 * MHZ, 6, 2);
// re-configure sys_clk to use PLL
clock_configure(clk_sys, CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS, 126 * MHZ, 126 * MHZ);
// re-configure CLK PERI = clk_sys
clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS, 126 * MHZ, 126 * MHZ);
}
int main()
{
setup_clocks();
stdio_init_all();
draw_demo();

30
src/vga.c
View File

@ -5,6 +5,8 @@
#include "hardware/dma.h"
#include "hardware/pio.h"
#include "hardware/structs/pio.h"
#include "hardware/clocks.h"
#include "hardware/pll.h"
#include "framebuffer.h"
#include "vga.pio.h"
@ -26,6 +28,30 @@ static int dma_channel;
unsigned long int frame_counter = 0;
static void setup_clocks(void)
{
// disable resuscitation clock
clocks_hw->resus.ctrl = 0;
// before changing PLL, switch sys and ref cleanly away from their aux sources
hw_clear_bits(&clocks_hw->clk[clk_sys].ctrl, CLOCKS_CLK_SYS_CTRL_SRC_BITS);
while (clocks_hw->clk[clk_sys].selected != 0x1)
tight_loop_contents();
hw_clear_bits(&clocks_hw->clk[clk_ref].ctrl, CLOCKS_CLK_REF_CTRL_SRC_BITS);
while (clocks_hw->clk[clk_ref].selected != 0x1)
tight_loop_contents();
// set PLL at 126 MHz, and wait for it to stabilize
pll_init(pll_sys, 1, 1512 * MHZ, 6, 2);
// re-configure sys_clk to use PLL
clock_configure(clk_sys, CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS, 126 * MHZ, 126 * MHZ);
// re-configure CLK PERI = clk_sys
clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS, 126 * MHZ, 126 * MHZ);
}
static void vga_pixel_program_init(PIO pio, uint sm, uint offset)
{
// config function automatically declared by SDK scripts
@ -115,6 +141,10 @@ void new_frame_handler(void)
void vga_machines_init(void)
{
// setup a proper system clock
// (126MHz = 4 x 31.5 MHz pixel clock)
setup_clocks();
// Running programs on PIO
vga_hsync.pio = vga_vsync.pio = vga_pixel.pio = pio0;