请问TM4C123GH6PM QEI是怎么配置的？

本例程仅供参考。
//****************************************************
//added qeiinit()
//****************************************************
void qeiinit()
[
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
SysCtlPeripheralEnable(SYSCTL_PERIPH_QEI0);

GPIOPinTypeQEI(GPIO_PORTD_BASE, GPIO_PIN_1);
GPIOPinTypeQEI(GPIO_PORTF_BASE, GPIO_PIN_7);
QEIConfigure(QEI0_BASE, (QEI_CONFIG_CAPTURE_A_B | QEI_CONFIG_NO_RESET|
QEI_CONFIG_QUADRATURE | QEI_CONFIG_NO_SWAP), 3999);
QEIEnable(QEI0_BASE);
QEIPositionSet(QEI0_BASE,2000);
]

//****************************************************
//added qeipositionget()
//****************************************************
void qeipositionget()
[
unsigned long j;
while(1)
[
j=QEIPositionGet(QEI0_BASE);
j=j;
]
]

int
main(void)
[
ROM_SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_8MHZ);

qeiinit();
qeipositionget();
]

谢谢