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Diff: targets/TARGET_NXP/TARGET_LPC13XX/us_ticker.c
- Revision:
- 149:156823d33999
- Parent:
- 144:ef7eb2e8f9f7
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/TARGET_NXP/TARGET_LPC13XX/us_ticker.c Fri Oct 28 11:17:30 2016 +0100 @@ -0,0 +1,62 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include <stddef.h> +#include "us_ticker_api.h" +#include "PeripheralNames.h" + +#define US_TICKER_TIMER ((LPC_CT32B1_Type *)LPC_CT32B1_BASE) +#define US_TICKER_TIMER_IRQn CT32B1_IRQn + +int us_ticker_inited = 0; + +void us_ticker_init(void) { + if (us_ticker_inited) return; + us_ticker_inited = 1; + + LPC_SYSCON->SYSAHBCLKCTRL |= (1<<10); // Clock TIMER_1 + uint32_t PCLK = SystemCoreClock; + + US_TICKER_TIMER->TCR = 0x2; // reset + + uint32_t prescale = PCLK / 1000000; // default to 1MHz (1 us ticks) + US_TICKER_TIMER->PR = prescale - 1; + US_TICKER_TIMER->TCR = 1; // enable = 1, reset = 0 + + NVIC_SetVector(US_TICKER_TIMER_IRQn, (uint32_t)us_ticker_irq_handler); + NVIC_EnableIRQ(US_TICKER_TIMER_IRQn); +} + +uint32_t us_ticker_read() { + if (!us_ticker_inited) + us_ticker_init(); + + return US_TICKER_TIMER->TC; +} + +void us_ticker_set_interrupt(timestamp_t timestamp) { + // set match value + US_TICKER_TIMER->MR0 = (uint32_t)timestamp; + // enable match interrupt + US_TICKER_TIMER->MCR |= 1; +} + +void us_ticker_disable_interrupt(void) { + US_TICKER_TIMER->MCR &= ~1; +} + +void us_ticker_clear_interrupt(void) { + US_TICKER_TIMER->IR = 1; +}