mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_NXP/TARGET_LPC176X/us_ticker.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
188:bcfe06ba3d64 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include <stddef.h>
<> 144:ef7eb2e8f9f7 17 #include "us_ticker_api.h"
<> 144:ef7eb2e8f9f7 18 #include "PeripheralNames.h"
<> 144:ef7eb2e8f9f7 19
Anna Bridge 186:707f6e361f3e 20 const ticker_info_t* us_ticker_get_info()
Anna Bridge 186:707f6e361f3e 21 {
Anna Bridge 186:707f6e361f3e 22 static const ticker_info_t info = {
Anna Bridge 186:707f6e361f3e 23 1000000, // 1 MHz
Anna Bridge 186:707f6e361f3e 24 32 // 32 bit counter
Anna Bridge 186:707f6e361f3e 25 };
Anna Bridge 186:707f6e361f3e 26 return &info;
Anna Bridge 186:707f6e361f3e 27 }
Anna Bridge 186:707f6e361f3e 28
Anna Bridge 186:707f6e361f3e 29 static bool us_ticker_inited = false;
Anna Bridge 186:707f6e361f3e 30
AnnaBridge 188:bcfe06ba3d64 31 #if MBED_CONF_TARGET_US_TICKER_TIMER == 0
AnnaBridge 188:bcfe06ba3d64 32 #define US_TICKER_TIMER ((LPC_TIM_TypeDef *)LPC_TIM0_BASE)
AnnaBridge 188:bcfe06ba3d64 33 #define US_TICKER_TIMER_IRQn TIMER0_IRQn
AnnaBridge 188:bcfe06ba3d64 34 #elif MBED_CONF_TARGET_US_TICKER_TIMER == 1
AnnaBridge 188:bcfe06ba3d64 35 #define US_TICKER_TIMER ((LPC_TIM_TypeDef *)LPC_TIM1_BASE)
AnnaBridge 188:bcfe06ba3d64 36 #define US_TICKER_TIMER_IRQn TIMER1_IRQn
AnnaBridge 189:f392fc9709a3 37 #elif MBED_CONF_TARGET_US_TICKER_TIMER == 2
AnnaBridge 188:bcfe06ba3d64 38 #define US_TICKER_TIMER ((LPC_TIM_TypeDef *)LPC_TIM2_BASE)
AnnaBridge 188:bcfe06ba3d64 39 #define US_TICKER_TIMER_IRQn TIMER2_IRQn
AnnaBridge 188:bcfe06ba3d64 40 #else
<> 144:ef7eb2e8f9f7 41 #define US_TICKER_TIMER ((LPC_TIM_TypeDef *)LPC_TIM3_BASE)
<> 144:ef7eb2e8f9f7 42 #define US_TICKER_TIMER_IRQn TIMER3_IRQn
AnnaBridge 188:bcfe06ba3d64 43 #endif
<> 144:ef7eb2e8f9f7 44
Anna Bridge 186:707f6e361f3e 45 void us_ticker_init(void) {
Anna Bridge 186:707f6e361f3e 46 if (us_ticker_inited) {
Anna Bridge 186:707f6e361f3e 47 /* calling init again should cancel current interrupt */
Anna Bridge 186:707f6e361f3e 48 us_ticker_disable_interrupt();
Anna Bridge 186:707f6e361f3e 49 return;
Anna Bridge 186:707f6e361f3e 50 }
Anna Bridge 186:707f6e361f3e 51 us_ticker_inited = true;
<> 144:ef7eb2e8f9f7 52
<> 144:ef7eb2e8f9f7 53 LPC_SC->PCONP |= 1 << 23; // Clock TIMER_3
Anna Bridge 186:707f6e361f3e 54
<> 144:ef7eb2e8f9f7 55 US_TICKER_TIMER->CTCR = 0x0; // timer mode
<> 144:ef7eb2e8f9f7 56 uint32_t PCLK = SystemCoreClock / 4;
Anna Bridge 186:707f6e361f3e 57
<> 144:ef7eb2e8f9f7 58 US_TICKER_TIMER->TCR = 0x2; // reset
Anna Bridge 186:707f6e361f3e 59
<> 144:ef7eb2e8f9f7 60 uint32_t prescale = PCLK / 1000000; // default to 1MHz (1 us ticks)
<> 144:ef7eb2e8f9f7 61 US_TICKER_TIMER->PR = prescale - 1;
<> 144:ef7eb2e8f9f7 62 US_TICKER_TIMER->TCR = 1; // enable = 1, reset = 0
Anna Bridge 186:707f6e361f3e 63
<> 144:ef7eb2e8f9f7 64 NVIC_SetVector(US_TICKER_TIMER_IRQn, (uint32_t)us_ticker_irq_handler);
<> 144:ef7eb2e8f9f7 65 NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
<> 144:ef7eb2e8f9f7 66 }
<> 144:ef7eb2e8f9f7 67
<> 144:ef7eb2e8f9f7 68 uint32_t us_ticker_read() {
<> 144:ef7eb2e8f9f7 69 return US_TICKER_TIMER->TC;
<> 144:ef7eb2e8f9f7 70 }
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 void us_ticker_set_interrupt(timestamp_t timestamp) {
<> 144:ef7eb2e8f9f7 73 // set match value
<> 144:ef7eb2e8f9f7 74 US_TICKER_TIMER->MR0 = (uint32_t)timestamp;
<> 144:ef7eb2e8f9f7 75 // enable match interrupt
<> 144:ef7eb2e8f9f7 76 US_TICKER_TIMER->MCR |= 1;
<> 144:ef7eb2e8f9f7 77 }
<> 144:ef7eb2e8f9f7 78
AnnaBridge 174:b96e65c34a4d 79 void us_ticker_fire_interrupt(void)
AnnaBridge 174:b96e65c34a4d 80 {
AnnaBridge 174:b96e65c34a4d 81 NVIC_SetPendingIRQ(US_TICKER_TIMER_IRQn);
AnnaBridge 174:b96e65c34a4d 82 }
AnnaBridge 174:b96e65c34a4d 83
<> 144:ef7eb2e8f9f7 84 void us_ticker_disable_interrupt(void) {
<> 144:ef7eb2e8f9f7 85 US_TICKER_TIMER->MCR &= ~1;
<> 144:ef7eb2e8f9f7 86 }
<> 144:ef7eb2e8f9f7 87
<> 144:ef7eb2e8f9f7 88 void us_ticker_clear_interrupt(void) {
<> 144:ef7eb2e8f9f7 89 US_TICKER_TIMER->IR = 1;
<> 144:ef7eb2e8f9f7 90 }
AnnaBridge 188:bcfe06ba3d64 91
AnnaBridge 188:bcfe06ba3d64 92 void us_ticker_free(void)
AnnaBridge 188:bcfe06ba3d64 93 {
AnnaBridge 188:bcfe06ba3d64 94 US_TICKER_TIMER->TCR = 0;
AnnaBridge 188:bcfe06ba3d64 95
AnnaBridge 188:bcfe06ba3d64 96 US_TICKER_TIMER->MCR &= ~1;
AnnaBridge 188:bcfe06ba3d64 97 NVIC_DisableIRQ(US_TICKER_TIMER_IRQn);
AnnaBridge 188:bcfe06ba3d64 98 }