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#include <stdint.h>
#include "ch573/gpio.h"
#define GPIO_PORT_A ch573_gpio__gpio_port_a
#define GPIO_PORT CH573_GPIO__GPIO_PORT_T_INTF
static void start(void);
/*
* Function (or really pointer to code) for the reset interrupt handler.
*/
void on_reset(void);
/*
* Function which delays for a bit.
*/
void delay(void);
/* Type def to a void function to make things mor ereadable. */
typedef void (*isr_routine)(void);
/** The ISR Vector structure. This is linked to starting at address 0. */
// __attribute((__section__(".isr_vector"))) volatile struct {
// // What NULL points to. nothing useful.
// uint32_t reserved__;
// // Called when the device boots or reset is pressed.
// isr_routine reset_cb;
// isr_routine nmi_cb;
// isr_routine exc_cb;
// } isr_vectors = {.reset_cb = on_reset};
/*
* The reset callback.This has to be a naked function because the stack pointer
* may not be initialized!!.
*/
__attribute((naked)) void on_reset(void)
{
// Set up the stack pointer to point to the end of SRAM.
asm volatile(
"li sp,0x20008000\n"
"addi sp,sp,-4\n"
"jalr %0\n"
"spin:\n"
"j spin\n"
:
: "r"(start));
}
uint32_t collatz(uint32_t n)
{
uint32_t c = 0;
while (n > 1) {
if (n % 2 == 0) {
n /= 2;
} else {
n = n * 3 + 1;
}
c++;
}
return c;
}
void blink_n(int n)
{
uint32_t bit = 1 << 8;
while (n > 0) {
GPIO_PORT.out.set(GPIO_PORT_A, OFF, 8);
delay();
GPIO_PORT.out.set(GPIO_PORT_A, ON, 8);
delay();
--n;
}
}
void delay(void)
{
for (volatile uint32_t i = 0; i < 10000; ++i);
}
/* Main routine. This is called on_reset once everything else has been set up.
*/
static void start(void)
{
GPIO_PORT.dir.set(GPIO_PORT_A, DIR_OUT, 8);
GPIO_PORT.pd_drv.set(GPIO_PORT_A, PD_DRV_OPEN_DRAIN, 8);
for (;;) {
GPIO_PORT.out.set(GPIO_PORT_A, ON, 8);
delay();
delay();
delay();
GPIO_PORT.out.set(GPIO_PORT_A, OFF, 8);
delay();
}
// uint32_t i;
// for (i = 1;; ++i) {
// uint32_t c = collatz(i);
// blink_n(c);
// delay();
// delay();
// delay();
// delay();
// delay();
// delay();
// delay();
// delay();
// delay();
// }
}
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