F28M35x M3 CAN配置，Pin脚没有输出，求助！

按照例程can_loopback_m3测试正常，但是希望修改为非测试模式，使用GPIO输入输出，

配置如下，但是GPIO没有输出？

不知要如何配置，求助！

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);

GPIOPinConfigure(GPIO_PE6_CAN0RX);
GPIOPinConfigure(GPIO_PE7_CAN0TX);

GPIOPinTypeCAN(GPIO_PORTE_BASE, GPIO_PIN_6 | GPIO_PIN_7);

SysCtlPeripheralEnable(SYSCTL_PERIPH_CAN0);

// Initialize the CAN controller
CANInit(CAN0_BASE);

// Setup CAN to be clocked off the M3/Master subsystem clock
CANClkSourceSelect(CAN0_BASE, CAN_CLK_M3);

/
CANBitRateSet(CAN0_BASE, SysCtlClockGet(SYSTEM_CLOCK_SPEED), 500000);

CANIntEnable(CAN0_BASE, CAN_INT_MASTER | CAN_INT_ERROR | CAN_INT_STATUS);

IntRegister(INT_CAN0INT0, CANIntHandler);

// Enable the CAN interrupt on the processor (NVIC).
IntEnable(INT_CAN0INT0);
IntMasterEnable();

// Enable test mode and select external loopback
HWREG(CAN0_BASE + CAN_O_CTL) |= CAN_CTL_CCE;
// HWREG(CAN0_BASE + CAN_O_TEST) = CAN_TEST_EXL;

// Enable the CAN for operation.
CANEnable(CAN0_BASE);