Content originally posted in LPCWare by jschimpf255 on Mon Mar 09 09:00:18 MST 2015
Hi,
I was wanting to use the capture registers on the LPC1114 timers. While there were many examples none seemed to use the Chip library that comes with lpcopen_v2_00a_lpcxpresso_nxp_lpcxpresso_11c24 set of examples and code. To rectify that here is a simple example to set up CAP0 for the the 16 bit timer 0 written using these functions.
Chip_TIMER_Init(LPC_TIMER16_0);
// LPC114 Manual Page 75 ICON_PIO0_2 register 0x4004 401C)
// 0x10 => Turn pullup
Chip_IOCON_PinMuxSet(LPC_IOCON, IOCON_PIO0_2, IOCON_FUNC2 | 0x10);
Chip_TIMER_CaptureFallingEdgeEnable(LPC_TIMER16_0,0);// Falling edge
Chip_TIMER_CaptureEnableInt(LPC_TIMER16_0,0);// Enable INT
Chip_TIMER_Enable(LPC_TIMER16_0); // Start timer
NVIC_EnableIRQ(TIMER_16_0_IRQn);// Turn on int
Right after this step the capture is armed and will in this case generate an interrupt calling:
void TIMER16_0_IRQHandler(void)
{
// Clear the capture interrupt
Chip_TIMER_ClearCapture(LPC_TIMER16_0,0); // You have to do this
:
:
Any other interrupt actions.
If you want to disable the capture temporally you just:
// Disable the INPUTS with the MUX
Chip_IOCON_PinMuxSet(LPC_IOCON, IOCON_PIO0_2, IOCON_FUNC0 | 0x10);
To re-enable
// Turn on the inputs with the MUX
Chip_IOCON_PinMuxSet(LPC_IOCON, IOCON_PIO0_2, IOCON_FUNC2 | 0x10);
You can see the Chip timer library for many more functions for setting edge conditions, match interrupts and other timer related functions.
--jim schimpf
