类似单总线，但是对时钟要求比较高，需要能精细到0.5微秒的延时，记得传输数据前需要拉低至少50微秒.

#include <stdio.h>
#include <stdbool.h>
#include "datasheet.h"
#include "gpio.h"

#define RGB_PORT         GPIO_PORT_0
#define RGB_PIN          GPIO_PIN_3

void set_colori(uint32_t color) {
    //author:yoyo(http://yoyo.play175.com/p/da14580-ws2813.html)
    int i;
    for(i = 0; i < 24; ++i) {
        if(color & 1) {
            SetWord16(GPIO_BASE + (RGB_PORT << 5) + 2, 1 << RGB_PIN);
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            SetWord16(GPIO_BASE + (RGB_PORT << 5) + 4, 1 << RGB_PIN);
            __nop();
            __nop();
        } else {
            SetWord16(GPIO_BASE + (RGB_PORT << 5) + 2, 1 << RGB_PIN);
            __nop();
            __nop();
            SetWord16(GPIO_BASE + (RGB_PORT << 5) + 4, 1 << RGB_PIN);
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
            __nop();
        }
        color >>= 1;
    }
}

void set_color3(uint8_t r, uint8_t g, uint8_t b) {
    set_colori((b << 16) | (r << 8) | g);
}

void delay(int ms) {
    unsigned int i = 2400 * ms;
    while(i--) {}
}

void system_init(void) {
    SetWord16(CLK_AMBA_REG, 0x00);                 // set clocks (hclk and pclk ) 16MHz
    SetWord16(SET_FREEZE_REG, FRZ_WDOG);           // stop watch dog
    SetBits16(SYS_CTRL_REG, PAD_LATCH_EN, 1);      // open pads
    SetBits16(SYS_CTRL_REG, DEBUGGER_ENABLE, 1);   // open debugger
    SetBits16(PMU_CTRL_REG, PERIPH_SLEEP, 0);      // exit peripheral power down
}

int main (void) {
    system_init();

    GPIO_ConfigurePin(RGB_PORT, RGB_PIN, OUTPUT, PID_GPIO, false);
    SetWord16(GPIO_BASE + (RGB_PORT << 5) + 4, 1 << RGB_PIN);
    delay(1);

    set_color3(0xff,0,0);

    while(1);
}