BK7256—pwm接口资料：
PWM — 博通集成 ARMINO 开发框架 文档
应用步骤：
1.在cpu0或者cpu1的配置文件【bk7256.config/bk7256_cp1.config】中添加宏定义CONFIG_PWM=y 【取决于你在哪个核使用PWM】
2.测试代码：【4KHz蜂鸣器每秒响1次】
#include "bk_private/bk_init.h"
#include <driver/pwm.h>
#include "pwm_hal.h"#ifdef CONFIG_CACHE_CUSTOM_SRAM_MAPPING
const unsigned int g_sram_addr_map[4] ={0x38000000,0x30020000,0x38020000,0x30000000};
#endif#define BUZZ_PWM_ID PWM_ID_11 // beep gpio对应的pwm号
#define BUZZ_FREQ (4000) // Buzz pwm 4000HZ
#define BUZZ_PERIOD (26000000 / BUZZ_FREQ) // SystemClk=26Mhzstatic int g_beep_cnt = 0;
static void make_beep(int cnt)
{g_beep_cnt += cnt;
}
static void buzz_thread(void *para)
{// buzz pwm initialbk_pwm_driver_init();pwm_init_config_t config = {0};config.period_cycle = BUZZ_PERIOD;config.duty_cycle = 0.5 * BUZZ_PERIOD; // 50% Pwm Dutyconfig.duty2_cycle = 0;config.duty3_cycle = 0;bk_pwm_init(BUZZ_PWM_ID, &config);bk_pwm_stop(BUZZ_PWM_ID);// loop logicwhile (1){if (g_beep_cnt > 0){g_beep_cnt--;bk_pwm_start(BUZZ_PWM_ID);rtos_delay_milliseconds(150);bk_pwm_stop(BUZZ_PWM_ID);if (g_beep_cnt > 5) // 防止Buzz狂响g_beep_cnt = 0;}rtos_delay_milliseconds(10);}
}int main(void)
{//bk_printf_rawbk_init();BK_LOG_RAW("[bk7256] main program build:%s %s.\n", __DATE__, __TIME__);BK_LOG_RAW("Buzz frequency:%d Hz.\n",BUZZ_FREQ);rtos_create_thread(NULL, 10, "buzz_thread", buzz_thread, 2 * 4096, NULL);while (1){ // beep sound every 1 secondmake_beep(1);rtos_delay_milliseconds(1000);}return 0;
}3.编译： make bk7256 PROJECT=项目相对路径 ，可以做成脚本。
4.烧录技巧：生成的bin文件一般是 armino/build/项目名/bk7256/all-app.bin ，将BK7256的CEN(ChipEn)引脚拉倒串口助手的RTS信号，辅助烧录时自动复位。
