CH573如何从用户程序进入ISP模式？

CH573可以实现从用户程序进入ISP模式：

void EnterCodeUpgrade (void)

{

FLASH_ROM_LOCK(0);

FLASH_ROM_ERASE( 0, 4096 );

R8_SAFE_ACCESS_SIG = SAFE_ACCESS_SIG1;

R8_SAFE_ACCESS_SIG = SAFE_ACCESS_SIG2;

R16_INT32K_TUNE = 0xFFFF;

R8_RST_WDOG_CTRL |= RB_SOFTWARE_RESET;

R8_SAFE_ACCESS_SIG = 0;

while(1);

}