sleep.c

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "sleep_api.h"
00017 
00018 #if DEVICE_SLEEP
00019 
00020 #include "cmsis.h"
00021 #include "mbed_interface.h"
00022 
00023 void sleep(void) {
00024 #if DEVICE_SEMIHOST
00025     // ensure debug is disconnected
00026     mbed_interface_disconnect();
00027 #endif
00028 
00029     // PCON[PD] set to sleep
00030 #if defined(TARGET_LPC11U24)
00031     LPC_PMU->PCON = 0x0;
00032 #elif defined(TARGET_LPC1768)
00033     LPC_SC->PCON = 0x0;
00034 #endif
00035 
00036     // SRC[SLEEPDEEP] set to 0 = sleep
00037     SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;
00038 
00039     // wait for interrupt
00040     __WFI();
00041 }
00042 
00043 /*
00044 * The mbed lpc1768 does not support the deepsleep mode
00045 * as a debugger is connected to it (the mbed interface).
00046 *
00047 * As mentionned in an application note from NXP:
00048 *
00049 *       http://www.po-star.com/public/uploads/20120319123122_141.pdf
00050 *
00051 *       {{{
00052 *       The user should be aware of certain limitations during debugging.
00053 *       The most important is that, due to limitations of the Cortex-M3
00054 *       integration, the LPC17xx cannot wake up in the usual manner from
00055 *       Deep Sleep and Power-down modes. It is recommended not to use these
00056 *       modes during debug. Once an application is downloaded via JTAG/SWD
00057 *       interface, the USB to SWD/JTAG debug adapter (Keil ULINK2 for example)
00058 *       should be removed from the target board, and thereafter, power cycle
00059 *       the LPC17xx to allow wake-up from deep sleep and power-down modes
00060 *       }}}
00061 *
00062 *       As the interface firmware does not reset the target when a
00063 *       mbed_interface_disconnect() semihosting call is made, the
00064 *       core cannot wake-up from deepsleep.
00065 *
00066 *       We treat a deepsleep() as a normal sleep().
00067 */
00068 
00069 void deepsleep(void) {
00070 #if DEVICE_SEMIHOST
00071     // ensure debug is disconnected
00072     mbed_interface_disconnect();
00073 #endif
00074 
00075     // PCON[PD] set to deepsleep
00076 #if defined(TARGET_LPC11U24)
00077     LPC_PMU->PCON = 0x1;
00078 
00079     // SRC[SLEEPDEEP] set to 1 = deep sleep
00080     SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
00081 
00082     // Power up everything after powerdown
00083     LPC_SYSCON->PDAWAKECFG &= 0xFFFFF800;
00084 
00085     // wait for interrupt
00086     __WFI();
00087 
00088 #elif defined(TARGET_LPC1768)
00089     sleep();
00090 #endif
00091 }
00092 
00093 #endif