Fixed with HAL.
Fork of ST_L152_32MHZ by
Not finish yet. External crystal doesn't work.
ST_L152_32MHZ.cpp
- Committer:
- dreschpe
- Date:
- 2014-03-11
- Revision:
- 1:bdeac50afe1a
- Parent:
- 0:84e23a19e37d
- Child:
- 2:9e2ba1d93567
File content as of revision 1:bdeac50afe1a:
/* mbed library for the ST NUCLEO board L152RE * to change the CPU clock to 32 MHz * A pll clock of 96 MHz is used to enable USB * * Copyright (c) 2014 Peter Drescher - DC2PD * Released under the MIT License: http://mbed.org/license/mit * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "stm32l1xx.h" #include "stm32l1xx_flash.h" #include "stm32l1xx_rcc.h" #include "ST_L152_32MHZ.h" // only the constructor L152_init32::L152_init32(unsigned int external){ Status = setup_clock_32MHZ(external); } #define PLL_STARTUP_TIMEOUT 0x5000 ClockStatus L152_init32::setup_clock_32MHZ(int external) { uint32_t PLLStartUpCounter = 0,PLLStatus = 0,error; if(external == 0) { // internal Oscillator RCC_PLLConfig(RCC_PLLSource_HSI,RCC_PLLMul_6,RCC_PLLDiv_3); // setup pll to 96MHz to use USB } else { RCC_HSEConfig(RCC_HSE_ON); // start external crystal osc. error = RCC_WaitForHSEStartUp(); if(error == ERROR ) { // no external crystal return(EXT_ERR); } RCC_PLLConfig(RCC_PLLSource_HSE,RCC_PLLMul_12,RCC_PLLDiv_3); // setup pll to 96MHz to use USB } RCC_PLLCmd(ENABLE); // switch on pll do { PLLStatus = RCC->CR & RCC_CR_PLLRDY; } while((PLLStatus == 0) && (PLLStartUpCounter < PLL_STARTUP_TIMEOUT)); // wait for pll if(PLLStatus == 0) { return(PLL_ERR); } FLASH_SetLatency(FLASH_Latency_1); FLASH_PrefetchBufferCmd(ENABLE); FLASH_ReadAccess64Cmd(ENABLE); RCC_HCLKConfig(RCC_SYSCLK_Div2); RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); // switch to 32 MHz clock SystemCoreClockUpdate(); // update SystemCoreClock var return(OK); }