GPIO 下拉电阻配置-TI中文支持网

我用的板子是TM4C1294NCPD 我想配置PJ0接口链接switch1，输入模式，并且使用下拉电阻。一下是我的配置代码，但是我下载到板子后，按下开关，PJ0电压依然为0.

void SW_Init(void){

SYSCTL->RCGCGPIO |= 0x00000100; // activate clock for Port J

while((SYSCTL->PRGPIO&0x00000100) == 0){;} // allow time for clock to stabilize

GPIOJ_AHB->DIR &= ~0x01; // make PJ0 in //& PJ1 in

GPIOJ_AHB->AFSEL &= ~0x01; // disable alt funct on PJ0 & PJ1

GPIOJ_AHB->PUR |= 0x00; // disable pull-up on PJ0

GPIOJ_AHB->PDR |= 0x01; // enable pull-down on PJ0

GPIOJ_AHB->DEN |= 0x01; // enable digital I/O on PJ0 //& PJ1

GPIOJ_AHB->AMSEL &= ~0x01; // disable analog functionality on PJ0 //& PJ1

GPIOJ_AHB->PCTL = (GPIOJ_AHB->PCTL & 0xFFFFFFF0)+0x00000000;

GPIOJ_AHB->IM &=~0x01; // Clear GPIOM before programming GPIOS,GPIOBE,GPIOEV

GPIOJ_AHB->ICR|= 0x01; // Clear Interrupt Flag

GPIOJ_AHB->IS &=~0x01; // PJ0 is edge-sensitive //& PJ1 are

GPIOJ_AHB->IBE &=~0x01; // PJ0 & PJ1 Interrupt is triggered by single edge

// GPIOJ_AHB->IEV &=~0x01; // PJ0 Interrupt is triggered by falling edge

GPIOJ_AHB->IEV |= 0x01; // PJ0 Interrupt is triggered by rising edge

GPIOJ_AHB->IM |= 0x01; // Enable PJ0 //& PJ1

NVIC_EN1_R |=0x00080000; // Enable Interrupt number 51 which is bit 19 in EN1

NVIC_PRI12_R = (NVIC_PRI12_R&0x00FFFFFF)|0x80000000; //Set the priority value to 4 in INTD of PRI12 Register. (page 159/160)

}

请去mcu论坛咨询。
e2echina.ti.com/…/

GPIO 下拉电阻配置