灵动MM32F0130时钟PLL到72Mhz,IO口发送脉冲,低电平会变宽,C和汇编测试都存在这种情况,发生这种情况的原因是什么?是时钟不稳定吗?
C程序
while(1)
{
GPIOB->BSRR = GPIO_Pin_3;
GPIOB->BRR = GPIO_Pin_3;
}
汇编程序
AREA ctesr,CODE,READONLY
EXPORT scan_test
GPIOB_BSRR EQU 0X48000410
GPIOB_BRR EQU 0X48000414
scan_test
MOVS R1,#0X01
LDR R2,=GPIOB_BSRR
LDR R3,=GPIOB_BRR
SENDS
STR R1,[R2]
STR R1,[R3]
B SENDS
end