Lancaster University / mbed-src

Lancaster University's (short term!) clone of mbed-src for micro:bit. This is a copy of the github branch https://github.com/lancaster-university/mbed-classic

Fork of mbed-src by mbed official

common/board.c@641:be9b2017785a, 2016-07-13 (annotated)

Committer:
LancasterUniversity
Date:
Wed Jul 13 12:52:54 2016 +0100
Revision:
641:be9b2017785a
Parent:
604:19d487c995ec 
Synchronized with git rev 1fb8ab4c

Author: James Devine

mbed-classic: BUGFIX for timer when using wait_ms from interrupt context



Previously if a user used wait[_ms,_us] in interrupt context the device would

hang indefinitely. This was due to incrementing overflowCount from

interrupt context only.



This meant that if a user used wait[_ms,_us] in an ISR with

the same or greater interrupt priority, it would result in an infinite

loop as the overflowCount variable would never be incremented, and

wait[_ms,_us] would never return.



This patch simply applies a better solution for the race condition

mentioned in the previous commit. It instead disables the timer1

interrupt and increments the overflowCount variable, preventing

the race condition whilst supporting wait[_ms,_us] in interrupt

context.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 4:c4bfb462ca53 1 /* mbed Microcontroller Library
emilmont 4:c4bfb462ca53 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 4:c4bfb462ca53 3 *
emilmont 4:c4bfb462ca53 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 4:c4bfb462ca53 5 * you may not use this file except in compliance with the License.
emilmont 4:c4bfb462ca53 6 * You may obtain a copy of the License at
emilmont 4:c4bfb462ca53 7 *
emilmont 4:c4bfb462ca53 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 4:c4bfb462ca53 9 *
emilmont 4:c4bfb462ca53 10 * Unless required by applicable law or agreed to in writing, software
emilmont 4:c4bfb462ca53 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 4:c4bfb462ca53 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 4:c4bfb462ca53 13 * See the License for the specific language governing permissions and
emilmont 4:c4bfb462ca53 14 * limitations under the License.
emilmont 4:c4bfb462ca53 15 */
emilmont 4:c4bfb462ca53 16 #include "gpio_api.h"
emilmont 4:c4bfb462ca53 17 #include "wait_api.h"
emilmont 4:c4bfb462ca53 18 #include "toolchain.h"
mbed_official 228:85a676113daa 19 #include "mbed_interface.h"
emilmont 4:c4bfb462ca53 20
emilmont 4:c4bfb462ca53 21 WEAK void mbed_die(void) {
mbed_official 604:19d487c995ec 22 #if !defined (NRF51_H) && !defined(TARGET_EFM32)
mbed_official 79:6fdc4ea80ae0 23 __disable_irq(); // dont allow interrupts to disturb the flash pattern
mbed_official 127:ce7cebc0511f 24 #endif
mbed_official 79:6fdc4ea80ae0 25 #if (DEVICE_ERROR_RED == 1)
mbed_official 113:65a335a675de 26 gpio_t led_red; gpio_init_out(&led_red, LED_RED);
mbed_official 79:6fdc4ea80ae0 27 #elif (DEVICE_ERROR_PATTERN == 1)
mbed_official 113:65a335a675de 28 gpio_t led_1; gpio_init_out(&led_1, LED1);
mbed_official 113:65a335a675de 29 gpio_t led_2; gpio_init_out(&led_2, LED2);
mbed_official 113:65a335a675de 30 gpio_t led_3; gpio_init_out(&led_3, LED3);
mbed_official 113:65a335a675de 31 gpio_t led_4; gpio_init_out(&led_4, LED4);
emilmont 4:c4bfb462ca53 32 #endif
mbed_official 221:8276e3a4886f 33
emilmont 4:c4bfb462ca53 34 while (1) {
mbed_official 79:6fdc4ea80ae0 35 #if (DEVICE_ERROR_RED == 1)
emilmont 4:c4bfb462ca53 36 gpio_write(&led_red, 1);
emilmont 4:c4bfb462ca53 37
mbed_official 79:6fdc4ea80ae0 38 #elif (DEVICE_ERROR_PATTERN == 1)
emilmont 4:c4bfb462ca53 39 gpio_write(&led_1, 1);
emilmont 4:c4bfb462ca53 40 gpio_write(&led_2, 0);
emilmont 4:c4bfb462ca53 41 gpio_write(&led_3, 0);
emilmont 4:c4bfb462ca53 42 gpio_write(&led_4, 1);
emilmont 4:c4bfb462ca53 43 #endif
mbed_official 221:8276e3a4886f 44
emilmont 4:c4bfb462ca53 45 wait_ms(150);
emilmont 4:c4bfb462ca53 46
mbed_official 79:6fdc4ea80ae0 47 #if (DEVICE_ERROR_RED == 1)
emilmont 4:c4bfb462ca53 48 gpio_write(&led_red, 0);
emilmont 4:c4bfb462ca53 49
mbed_official 79:6fdc4ea80ae0 50 #elif (DEVICE_ERROR_PATTERN == 1)
emilmont 4:c4bfb462ca53 51 gpio_write(&led_1, 0);
emilmont 4:c4bfb462ca53 52 gpio_write(&led_2, 1);
emilmont 4:c4bfb462ca53 53 gpio_write(&led_3, 1);
emilmont 4:c4bfb462ca53 54 gpio_write(&led_4, 0);
emilmont 4:c4bfb462ca53 55 #endif
mbed_official 221:8276e3a4886f 56
emilmont 4:c4bfb462ca53 57 wait_ms(150);
emilmont 4:c4bfb462ca53 58 }
emilmont 4:c4bfb462ca53 59 }