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/******************************************************************************
* The MIT License
*
* Copyright (c) 2012 LeafLabs, LLC.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* 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.
*****************************************************************************/
/**
* @file wirish/stm32f2/boards_setup.cpp
* @author Marti Bolivar <mbolivar@leaflabs.com>
* @brief STM32F2 chip setup.
*
* This file controls how init() behaves on the STM32F2. Be very
* careful when changing anything here. Many of these values depend
* upon each other.
*/
#include "boards_private.h"
#include <libmaple/gpio.h>
#include <wirish/wirish_types.h>
// PLL configuration for 25 MHz external oscillator --> 120 MHz SYSCLK.
#define PLL_Q 5
#define PLL_P 2
#define PLL_N 240
#define PLL_M 25
static stm32f2_rcc_pll_data pll_data = {PLL_Q, PLL_P, PLL_N, PLL_M};
namespace wirish {
namespace priv {
// PLL clocked off of HSE, with above configuration data.
rcc_pll_cfg w_board_pll_cfg = {RCC_PLLSRC_HSE, &pll_data};
// As f_APB2 = 60 MHz (see board_setup_clock_prescalers),
// we need f_ADC = f_PCLK2 / 2 to get the (maximum)
// f_ADC = 30 MHz.
adc_prescaler w_adc_pre = ADC_PRE_PCLK2_DIV_2;
// With clocks as specified here (i.e. f_ADC = 30 MHz), this
// ADC sample rate allows for error less than 1/4 LSB with a
// 50 KOhm input impedance, assuming an internal sample and
// hold capacitance C_ADC at most 8.8 pF. See Equation 1 and
// Table 61 in the F2 datasheet for more details.
adc_smp_rate w_adc_smp = ADC_SMPR_144;
void board_reset_pll(void) {
// Set PLLCFGR to its reset value.
RCC_BASE->PLLCFGR = 0x24003010; // FIXME lose the magic number.
}
void board_setup_clock_prescalers(void) {
// With f_SYSCLK = 120 MHz (as determined by board_pll_cfg),
//
// f_AHB = f_SYSCLK / 1 = 120 MHz
rcc_set_prescaler(RCC_PRESCALER_AHB, RCC_AHB_SYSCLK_DIV_1);
// f_APB1 = f_AHB / 4 = 30 MHz
rcc_set_prescaler(RCC_PRESCALER_APB1, RCC_APB1_HCLK_DIV_4);
// f_APB2 = f_AHB / 2 = 60 MHz
rcc_set_prescaler(RCC_PRESCALER_APB2, RCC_APB2_HCLK_DIV_2);
}
void board_setup_gpio(void) {
gpio_init_all();
}
void board_setup_usb(void) {
// Nothing to do.
}
}
}
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