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mbed library sources

Dependents:   Encrypted my_mbed lklk CyaSSL_DTLS_Cellular ... more

Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

Import librarymbed

The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_NXP/TARGET_LPC81X/us_ticker.c@635:a11c0372f0ba, 2015-09-30 (annotated)

Committer:
mbed_official
Date:
Wed Sep 30 17:00:09 2015 +0100
Revision:
635:a11c0372f0ba
Parent:
614:9d86c2ae5de0 
Synchronized with git revision d29c98dae61be0946ddf3a3c641c7726056f9452



Full URL: https://github.com/mbedmicro/mbed/commit/d29c98dae61be0946ddf3a3c641c7726056f9452/



Added support for SAMW25

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 46:bebbbd80dd87 1 /* mbed Microcontroller Library
mbed_official 46:bebbbd80dd87 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 46:bebbbd80dd87 3 *
mbed_official 46:bebbbd80dd87 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 46:bebbbd80dd87 5 * you may not use this file except in compliance with the License.
mbed_official 46:bebbbd80dd87 6 * You may obtain a copy of the License at
mbed_official 46:bebbbd80dd87 7 *
mbed_official 46:bebbbd80dd87 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 46:bebbbd80dd87 9 *
mbed_official 46:bebbbd80dd87 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 46:bebbbd80dd87 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 46:bebbbd80dd87 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 46:bebbbd80dd87 13 * See the License for the specific language governing permissions and
mbed_official 46:bebbbd80dd87 14 * limitations under the License.
mbed_official 46:bebbbd80dd87 15 */
mbed_official 46:bebbbd80dd87 16 #include <stddef.h>
mbed_official 46:bebbbd80dd87 17 #include "us_ticker_api.h"
mbed_official 46:bebbbd80dd87 18 #include "PeripheralNames.h"
mbed_official 46:bebbbd80dd87 19
mbed_official 480:69aad4cbc07a 20 //New, using MRT instead of SCT, needed to free up SCT for PWM
mbed_official 480:69aad4cbc07a 21 //Ported from LPC824 libs
mbed_official 480:69aad4cbc07a 22 static int us_ticker_inited = 0;
mbed_official 614:9d86c2ae5de0 23 static int us_ticker_interrupt_inited = 0;
mbed_official 480:69aad4cbc07a 24 unsigned int ticker_fullcount_us;
mbed_official 480:69aad4cbc07a 25 unsigned long int ticker_expired_count_us = 0;
mbed_official 480:69aad4cbc07a 26 int MRT_Clock_MHz;
mbed_official 46:bebbbd80dd87 27
mbed_official 480:69aad4cbc07a 28 #define US_TICKER_TIMER_IRQn MRT_IRQn
mbed_official 46:bebbbd80dd87 29
mbed_official 46:bebbbd80dd87 30 void us_ticker_init(void) {
mbed_official 480:69aad4cbc07a 31
mbed_official 480:69aad4cbc07a 32 if (us_ticker_inited)
mbed_official 480:69aad4cbc07a 33 return;
mbed_official 480:69aad4cbc07a 34
mbed_official 46:bebbbd80dd87 35 us_ticker_inited = 1;
mbed_official 46:bebbbd80dd87 36
mbed_official 480:69aad4cbc07a 37 // Calculate MRT clock value (MRT has no prescaler)
mbed_official 480:69aad4cbc07a 38 MRT_Clock_MHz = (SystemCoreClock / 1000000);
mbed_official 480:69aad4cbc07a 39 // Calculate fullcounter value in us (MRT has 31 bits and clock is 30 MHz)
mbed_official 480:69aad4cbc07a 40 ticker_fullcount_us = 0x80000000UL/MRT_Clock_MHz;
mbed_official 480:69aad4cbc07a 41
mbed_official 480:69aad4cbc07a 42 // Enable the MRT clock
mbed_official 480:69aad4cbc07a 43 LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 10);
mbed_official 480:69aad4cbc07a 44
mbed_official 480:69aad4cbc07a 45 // Clear peripheral reset the MRT
mbed_official 480:69aad4cbc07a 46 LPC_SYSCON->PRESETCTRL |= (1 << 7);
mbed_official 480:69aad4cbc07a 47
mbed_official 480:69aad4cbc07a 48 // Force load interval value (Bit 0-30 is interval value, Bit 31 is Force Load bit)
mbed_official 480:69aad4cbc07a 49 LPC_MRT->INTVAL0 = 0xFFFFFFFFUL;
mbed_official 480:69aad4cbc07a 50 // Enable Ch0 interrupt, Mode 0 is Repeat Interrupt
mbed_official 480:69aad4cbc07a 51 LPC_MRT->CTRL0 = (0x0 << 1) | (0x1 << 0);
mbed_official 480:69aad4cbc07a 52
mbed_official 480:69aad4cbc07a 53 // Force load interval value (Bit 0-30 is interval value, Bit 31 is Force Load bit)
mbed_official 480:69aad4cbc07a 54 LPC_MRT->INTVAL1 = 0x80000000UL;
mbed_official 480:69aad4cbc07a 55 // Disable ch1 interrupt, Mode 0 is Repeat Interrupt
mbed_official 480:69aad4cbc07a 56 LPC_MRT->CTRL1 = (0x0 << 1) | (0x0 << 0);
mbed_official 614:9d86c2ae5de0 57 }
mbed_official 614:9d86c2ae5de0 58
mbed_official 614:9d86c2ae5de0 59 void us_ticker_interrupt_init(void) {
mbed_official 614:9d86c2ae5de0 60
mbed_official 614:9d86c2ae5de0 61 if (us_ticker_interrupt_inited)
mbed_official 614:9d86c2ae5de0 62 return;
mbed_official 614:9d86c2ae5de0 63
mbed_official 614:9d86c2ae5de0 64 us_ticker_interrupt_inited = 1;
mbed_official 614:9d86c2ae5de0 65
mbed_official 480:69aad4cbc07a 66 // Set MRT interrupt vector
mbed_official 46:bebbbd80dd87 67 NVIC_SetVector(US_TICKER_TIMER_IRQn, (uint32_t)us_ticker_irq_handler);
mbed_official 46:bebbbd80dd87 68 NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
mbed_official 46:bebbbd80dd87 69 }
mbed_official 46:bebbbd80dd87 70
mbed_official 480:69aad4cbc07a 71 //TIMER0 is used for us ticker and timers (Timer, wait(), wait_us() etc)
mbed_official 46:bebbbd80dd87 72 uint32_t us_ticker_read() {
mbed_official 480:69aad4cbc07a 73
mbed_official 46:bebbbd80dd87 74 if (!us_ticker_inited)
mbed_official 46:bebbbd80dd87 75 us_ticker_init();
mbed_official 480:69aad4cbc07a 76
mbed_official 480:69aad4cbc07a 77 // Generate ticker value
mbed_official 480:69aad4cbc07a 78 // MRT source clock is SystemCoreClock (30MHz) and MRT is a 31-bit countdown timer
mbed_official 480:69aad4cbc07a 79 // Calculate expected value using current count and number of expired times to mimic a 32bit timer @ 1 MHz
mbed_official 480:69aad4cbc07a 80 //
mbed_official 480:69aad4cbc07a 81 // ticker_expired_count_us
mbed_official 480:69aad4cbc07a 82 // The variable ticker_expired_count_us keeps track of the number of 31bits overflows (counted by TIMER0) and
mbed_official 480:69aad4cbc07a 83 // corrects that back to us counts.
mbed_official 480:69aad4cbc07a 84 //
mbed_official 480:69aad4cbc07a 85 // (0x7FFFFFFFUL - LPC_MRT->TIMER0)/MRT_Clock_MHz
mbed_official 480:69aad4cbc07a 86 // The counter is a 31bit downcounter from 7FFFFFFF so correct to actual count-up value and correct
mbed_official 480:69aad4cbc07a 87 // for 30 counts per us.
mbed_official 480:69aad4cbc07a 88 //
mbed_official 480:69aad4cbc07a 89 // Added up these 2 parts result in current us time returned as 32 bits.
mbed_official 480:69aad4cbc07a 90 return (0x7FFFFFFFUL - LPC_MRT->TIMER0)/MRT_Clock_MHz + ticker_expired_count_us;
mbed_official 46:bebbbd80dd87 91 }
mbed_official 46:bebbbd80dd87 92
mbed_official 480:69aad4cbc07a 93 //TIMER1 is used for Timestamped interrupts (Ticker(), Timeout())
mbed_official 304:89b9c3a9a045 94 void us_ticker_set_interrupt(timestamp_t timestamp) {
mbed_official 46:bebbbd80dd87 95
mbed_official 614:9d86c2ae5de0 96 if (!us_ticker_interrupt_inited)
mbed_official 614:9d86c2ae5de0 97 us_ticker_interrupt_init();
mbed_official 614:9d86c2ae5de0 98
mbed_official 480:69aad4cbc07a 99 // MRT source clock is SystemCoreClock (30MHz) and MRT is a 31-bit countdown timer
mbed_official 480:69aad4cbc07a 100 // Force load interval value (Bit 0-30 is interval value, Bit 31 is Force Load bit)
mbed_official 480:69aad4cbc07a 101 // Note: The MRT has less counter headroom available than the typical mbed 32bit timer @ 1 MHz.
mbed_official 480:69aad4cbc07a 102 // The calculated counter interval until the next timestamp will be truncated and an
mbed_official 480:69aad4cbc07a 103 // 'early' interrupt will be generated in case the max required count interval exceeds
mbed_official 480:69aad4cbc07a 104 // the available 31 bits space. However, the mbed us_ticker interrupt handler will
mbed_official 480:69aad4cbc07a 105 // check current time against the next scheduled timestamp and simply re-issue the
mbed_official 480:69aad4cbc07a 106 // same interrupt again when needed. The calculated counter interval will now be smaller.
mbed_official 480:69aad4cbc07a 107 LPC_MRT->INTVAL1 = (((timestamp - us_ticker_read()) * MRT_Clock_MHz) | 0x80000000UL);
mbed_official 46:bebbbd80dd87 108
mbed_official 480:69aad4cbc07a 109 // Enable interrupt
mbed_official 480:69aad4cbc07a 110 LPC_MRT->CTRL1 |= 1;
mbed_official 480:69aad4cbc07a 111 }
mbed_official 480:69aad4cbc07a 112
mbed_official 480:69aad4cbc07a 113 //Disable Timestamped interrupts triggered by TIMER1
mbed_official 480:69aad4cbc07a 114 void us_ticker_disable_interrupt() {
mbed_official 480:69aad4cbc07a 115 //Timer1 for Timestamped interrupts (31 bits downcounter @ SystemCoreClock)
mbed_official 480:69aad4cbc07a 116 LPC_MRT->CTRL1 &= ~1;
mbed_official 480:69aad4cbc07a 117 }
mbed_official 480:69aad4cbc07a 118
mbed_official 480:69aad4cbc07a 119 void us_ticker_clear_interrupt() {
mbed_official 480:69aad4cbc07a 120
mbed_official 480:69aad4cbc07a 121 //Timer1 for Timestamped interrupts (31 bits downcounter @ SystemCoreClock)
mbed_official 480:69aad4cbc07a 122 if (LPC_MRT->STAT1 & 1)
mbed_official 480:69aad4cbc07a 123 LPC_MRT->STAT1 = 1;
mbed_official 480:69aad4cbc07a 124
mbed_official 480:69aad4cbc07a 125 //Timer0 for us counter (31 bits downcounter @ SystemCoreClock)
mbed_official 480:69aad4cbc07a 126 if (LPC_MRT->STAT0 & 1) {
mbed_official 480:69aad4cbc07a 127 LPC_MRT->STAT0 = 1;
mbed_official 480:69aad4cbc07a 128 // ticker_expired_count_us = (ticker_expired * 0x80000000UL) / MRT_Clock_MHz
mbed_official 480:69aad4cbc07a 129 // The variable ticker_expired_count_us keeps track of the number of 31bits overflows (counted by TIMER0) and
mbed_official 480:69aad4cbc07a 130 // the multiplication/division corrects that back to us counts.
mbed_official 480:69aad4cbc07a 131 ticker_expired_count_us += ticker_fullcount_us;
mbed_official 46:bebbbd80dd87 132 }
mbed_official 46:bebbbd80dd87 133 }