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Merge pull request #11 "Add helper function for max clock on HSI for f100"

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Merge remote-tracking branch 'karlp/hsi_f1_24'
This commit is contained in:
Piotr Esden-Tempski 2012-06-27 13:58:14 -07:00
commit a70eabb3e1
2 changed files with 52 additions and 0 deletions
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5
include/libopencm3/stm32/f1/rcc.h
View File

@ -447,6 +447,11 @@ void rcc_set_usbpre(u32 usbpre);
u32 rcc_get_system_clock_source(int i);
void rcc_clock_setup_in_hsi_out_64mhz(void);
void rcc_clock_setup_in_hsi_out_48mhz(void);
/**
* Maximum speed possible for F100 (Value Line) on HSI
*/
void rcc_clock_setup_in_hsi_out_24mhz(void);
void rcc_clock_setup_in_hse_8mhz_out_24mhz(void);
void rcc_clock_setup_in_hse_8mhz_out_72mhz(void);
void rcc_clock_setup_in_hse_12mhz_out_72mhz(void);

47
lib/stm32/f1/rcc.c
View File

@ -486,6 +486,53 @@ void rcc_clock_setup_in_hsi_out_48mhz(void)
rcc_ppre2_frequency = 48000000;
}
void rcc_clock_setup_in_hsi_out_24mhz(void) {
/* Enable internal high-speed oscillator. */
rcc_osc_on(HSI);
rcc_wait_for_osc_ready(HSI);
/* Select HSI as SYSCLK source. */
rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
/*
* Set prescalers for AHB, ADC, ABP1, ABP2.
* Do this before touching the PLL (TODO: why?).
*/
rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 24MHz Max. 24MHz */
rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV2); /* Set. 12MHz Max. 12MHz */
rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_NODIV); /* Set. 24MHz Max. 24MHz */
rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 24MHz Max. 24MHz */
/*
* Sysclk is (will be) running with 24MHz -> 2 waitstates.
* 0WS from 0-24MHz
* 1WS from 24-48MHz
* 2WS from 48-72MHz
*/
flash_set_ws(FLASH_LATENCY_0WS);
/*
* Set the PLL multiplication factor to 6.
* 8MHz (internal) * 6 (multiplier) / 2 (PLLSRC_HSI_CLK_DIV2) = 24MHz
*/
rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL6);
/* Select HSI/2 as PLL source. */
rcc_set_pll_source(RCC_CFGR_PLLSRC_HSI_CLK_DIV2);
/* Enable PLL oscillator and wait for it to stabilize. */
rcc_osc_on(PLL);
rcc_wait_for_osc_ready(PLL);
/* Select PLL as SYSCLK source. */
rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
/* Set the peripheral clock frequencies used */
rcc_ppre1_frequency = 24000000;
rcc_ppre2_frequency = 24000000;
}
void rcc_clock_setup_in_hse_8mhz_out_24mhz(void)
{
/* Enable internal high-speed oscillator. */