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Merge pull request #2013 from egostm/spi_freq_selection 

Spi freq selection
pull/2062/head
Sam Grove 2016-06-28 17:43:43 -05:00 committed by GitHub
parent a6f640c3f8 bc08631931
commit a773b639d6
8 changed files with 313 additions and 496 deletions
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45
hal/targets/hal/TARGET_STM/TARGET_STM32F0/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -168,25 +169,33 @@ void spi_format(spi_t *obj, int bits, int mode, int slave) {
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) { void spi_frequency(spi_t *obj, int hz) {
// Note: The frequencies are obtained with SPI clock = 48 MHz (APB clock) int spi_hz = 0;
if (hz < 375000) { uint8_t prescaler_rank = 0;
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 188 kHz
} else if ((hz >= 375000) && (hz < 750000)) { /* SPI_1, SPI_2. Source CLK is PCKL1 */
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 375 kHz spi_hz = HAL_RCC_GetPCLK1Freq();
} else if ((hz >= 750000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 750 kHz /* Define pre-scaler in order to get highest available frequency below requested frequency */
} else if ((hz >= 1000000) && (hz < 3000000)) { while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.5 MHz spi_hz = spi_hz / 2;
} else if ((hz >= 3000000) && (hz < 6000000)) { prescaler_rank++;
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3 MHz }
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6 MHz if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
} else if ((hz >= 12000000) && (hz < 24000000)) { obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 12 MHz } else {
} else { // >= 24000000 error("Couldn't setup requested SPI frequency");
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 24 MHz }
}
init_spi(obj); init_spi(obj);
} }

75
hal/targets/hal/TARGET_STM/TARGET_STM32F1/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -168,49 +169,45 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
if (obj->spi == SPI_1) { int spi_hz = 0;
// Values depend of PCLK2: 64 MHz if HSI is used, 72 MHz if HSE is used uint8_t prescaler_rank = 0;
if (hz < 500000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 250 kHz - 281 kHz /* Get source clock depending on SPI instance */
} else if ((hz >= 500000) && (hz < 1000000)) { switch ((int)obj->spi) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 500 kHz - 563 kHz case SPI_1:
} else if ((hz >= 1000000) && (hz < 2000000)) { /* SPI_1. Source CLK is PCKL2 */
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1 MHz - 1.13 MHz spi_hz = HAL_RCC_GetPCLK2Freq();
} else if ((hz >= 2000000) && (hz < 4000000)) { break;
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2 MHz - 2.25 MHz case SPI_2:
} else if ((hz >= 4000000) && (hz < 8000000)) { /* SPI_2. Source CLK is PCKL1 */
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 4 MHz - 4.5 MHz spi_hz = HAL_RCC_GetPCLK1Freq();
} else if ((hz >= 8000000) && (hz < 16000000)) { break;
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 8 MHz - 9 MHz default:
} else if ((hz >= 16000000) && (hz < 32000000)) { error("SPI instance not set");
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 16 MHz - 18 MHz
} else { // >= 32000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 32 MHz - 36 MHz
}
} }
if (obj->spi == SPI_2) { /* Define pre-scaler in order to get highest available frequency below requested frequency */
// Values depend of PCLK1: 32 MHz if HSI is used, 36 MHz if HSE is used while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
if (hz < 250000) { spi_hz = spi_hz / 2;
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz - 141 kHz prescaler_rank++;
} else if ((hz >= 250000) && (hz < 500000)) { }
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz - 281 kHz
} else if ((hz >= 500000) && (hz < 1000000)) { if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz - 563 kHz obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
} else if ((hz >= 1000000) && (hz < 2000000)) { } else {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz - 1.13 MHz error("Couldn't setup requested SPI frequency");
} else if ((hz >= 2000000) && (hz < 4000000)) { }
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz - 2.25 MHz
} else if ((hz >= 4000000) && (hz < 8000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz - 4.5 MHz
} else if ((hz >= 8000000) && (hz < 16000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz - 9 MHz
} else { // >= 16000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz - 18 MHz
}
}
init_spi(obj); init_spi(obj);
} }

119
hal/targets/hal/TARGET_STM/TARGET_STM32F3/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -195,86 +196,52 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
#if defined(TARGET_STM32F334C8) int spi_hz = 0;
// Values depend of APB2CLK : 64 MHz if HSI is used, 72 MHz if HSE is used uint8_t prescaler_rank = 0;
if (hz < 500000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 250 kHz - 281 kHz /* Get source clock depending on SPI instance */
} else if ((hz >= 500000) && (hz < 1000000)) { switch ((int)obj->spi) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 500 kHz - 563 kHz #if defined SPI1_BASE
} else if ((hz >= 1000000) && (hz < 2000000)) { case SPI_1:
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1 MHz - 1.13 MHz /* SPI_1. Source CLK is PCKL2 */
} else if ((hz >= 2000000) && (hz < 4000000)) { spi_hz = HAL_RCC_GetPCLK2Freq();
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2 MHz - 2.25 MHz break;
} else if ((hz >= 4000000) && (hz < 8000000)) { #endif
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 4 MHz - 4.5 MHz #if defined SPI2_BASE
} else if ((hz >= 8000000) && (hz < 16000000)) { case SPI_2:
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 8 MHz - 9 MHz #endif
} else if ((hz >= 16000000) && (hz < 32000000)) { #if defined SPI3_BASE
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 16 MHz - 18 MHz case SPI_3:
} else { // >= 32000000 #endif
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 32 MHz - 36 MHz /* SPI_2 and SPI_3. Source CLK is PCKL1 */
} spi_hz = HAL_RCC_GetPCLK1Freq();
#elif defined(TARGET_STM32F302R8) break;
if (hz < 250000) { default:
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz - 141 kHz error("SPI instance not set");
} else if ((hz >= 250000) && (hz < 500000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz - 280 kHz
} else if ((hz >= 500000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz - 560 kHz
} else if ((hz >= 1000000) && (hz < 2000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz - 1.13 MHz
} else if ((hz >= 2000000) && (hz < 4000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz - 2.25 MHz
} else if ((hz >= 4000000) && (hz < 8000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz - 4.5 MHz
} else if ((hz >= 8000000) && (hz < 16000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz - 9 MHz
} else { // >= 16000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz - 18 MHz
} }
#else /* Define pre-scaler in order to get highest available frequency below requested frequency */
// Values depend of APB1CLK and APB2CLK : 32 MHz if HSI is used, 36 MHz if HSE is used while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
if (obj->spi == SPI_1) { spi_hz = spi_hz / 2;
if (hz < 500000) { prescaler_rank++;
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 250 kHz - 280 kHz }
} else if ((hz >= 500000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 500 kHz - 560 kHz if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
} else if ((hz >= 1000000) && (hz < 2000000)) { obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1 MHz - 1.13 MHz } else {
} else if ((hz >= 2000000) && (hz < 4000000)) { error("Couldn't setup requested SPI frequency");
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2 MHz - 2.25 MHz }
} else if ((hz >= 4000000) && (hz < 8000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 4 MHz - 4.5 MHz
} else if ((hz >= 8000000) && (hz < 16000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 8 MHz - 9 MHz
} else if ((hz >= 16000000) && (hz < 32000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 16 MHz - 18 MHz
} else { // >= 32000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 32 MHz - 36 MHz
}
} else {
if (hz < 250000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz - 141 kHz
} else if ((hz >= 250000) && (hz < 500000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz - 280 kHz
} else if ((hz >= 500000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz - 560 kHz
} else if ((hz >= 1000000) && (hz < 2000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz - 1.13 MHz
} else if ((hz >= 2000000) && (hz < 4000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz - 2.25 MHz
} else if ((hz >= 4000000) && (hz < 8000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz - 4.5 MHz
} else if ((hz >= 8000000) && (hz < 16000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz - 9 MHz
} else { // >= 16000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz - 18 MHz
}
}
#endif
init_spi(obj); init_spi(obj);
} }

273
hal/targets/hal/TARGET_STM/TARGET_STM32F4/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -227,232 +228,58 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
#if defined(TARGET_STM32F401RE) || defined(TARGET_STM32F401VC) || defined(TARGET_STM32F407VG) int spi_hz = 0;
// Note: The frequencies are obtained with SPI1 clock = 84 MHz (APB2 clock) uint8_t prescaler_rank = 0;
if (hz < 600000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 330 kHz /* Get source clock depending on SPI instance */
} else if ((hz >= 600000) && (hz < 1000000)) { switch ((int)obj->spi) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 656 kHz case SPI_1:
} else if ((hz >= 1000000) && (hz < 2000000)) { #if defined SPI4_BASE
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.3 MHz case SPI_4:
} else if ((hz >= 2000000) && (hz < 5000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2.6 MHz
} else if ((hz >= 5000000) && (hz < 10000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 5.25 MHz
} else if ((hz >= 10000000) && (hz < 21000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 10.5 MHz
} else if ((hz >= 21000000) && (hz < 42000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 21 MHz
} else { // >= 42000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 42 MHz
}
#elif defined(TARGET_STM32F405RG)
// Note: The frequencies are obtained with SPI1 clock = 48 MHz (APB2 clock)
if (obj->spi == SPI_1) {
if (hz < 375000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 187.5 kHz
} else if ((hz >= 375000) && (hz < 750000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 375 kHz
} else if ((hz >= 750000) && (hz < 1500000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 0.75 MHz
} else if ((hz >= 1500000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.5 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6 MHz
} else if ((hz >= 12000000) && (hz < 24000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 12 MHz
} else { // >= 24000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 24 MHz
}
// Note: The frequencies are obtained with SPI2/3 clock = 48 MHz (APB1 clock)
} else if ((obj->spi == SPI_2) || (obj->spi == SPI_3)) {
if (hz < 375000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 187.5 kHz
} else if ((hz >= 375000) && (hz < 750000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 375 kHz
} else if ((hz >= 750000) && (hz < 1500000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 0.75 MHz
} else if ((hz >= 1500000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.5 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6 MHz
} else if ((hz >= 12000000) && (hz < 24000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 12 MHz
} else { // >= 24000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 24 MHz
}
}
#elif defined(TARGET_STM32F411RE) || defined(TARGET_STM32F429ZI)
// Values depend of PCLK2: 100 MHz
if ((obj->spi == SPI_1) || (obj->spi == SPI_4) || (obj->spi == SPI_5)) {
if (hz < 700000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 391 kHz
} else if ((hz >= 700000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 781 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.56 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 3.13 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 6.25 MHz
} else if ((hz >= 12000000) && (hz < 25000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 12.5 MHz
} else if ((hz >= 25000000) && (hz < 50000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 25 MHz
} else { // >= 50000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 50 MHz
}
}
// Values depend of PCLK1: 50 MHz
if ((obj->spi == SPI_2) || (obj->spi == SPI_3)) {
if (hz < 400000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 195 kHz
} else if ((hz >= 400000) && (hz < 700000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 391 kHz
} else if ((hz >= 700000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 781 MHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.56 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3.13 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6.25 MHz
} else if ((hz >= 12000000) && (hz < 25000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 12.5 MHz
} else { // >= 25000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 25 MHz
}
}
#elif defined(TARGET_STM32F446RE)
// Values depend of PCLK2: 90 MHz
if ((obj->spi == SPI_1) || (obj->spi == SPI_4)) {
if (hz < 700000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 352 kHz
} else if ((hz >= 700000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 703 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.41 MHz
} else if ((hz >= 3000000) && (hz < 5000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2.81 MHz
} else if ((hz >= 5000000) && (hz < 11000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 5.63 MHz
} else if ((hz >= 11000000) && (hz < 22000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 11.25 MHz
} else if ((hz >= 22000000) && (hz < 45000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 22.5 MHz
} else { // >= 45000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 45 MHz
}
}
// Values depend of PCLK1: 45 MHz
if ((obj->spi == SPI_2) || (obj->spi == SPI_3)) {
if (hz < 350000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 176 kHz
} else if ((hz >= 350000) && (hz < 700000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 352 kHz
} else if ((hz >= 700000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 703 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.41 MHz
} else if ((hz >= 3000000) && (hz < 5000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2.81 MHz
} else if ((hz >= 5000000) && (hz < 11000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 5.63 MHz
} else if ((hz >= 11000000) && (hz < 22000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 11.25 MHz
} else { // >= 22000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 22.5 MHz
}
}
#elif defined(TARGET_STM32F469NI)
// Values depend of PCLK2: 84 MHz
if ((obj->spi == SPI_1) || (obj->spi == SPI_4)) {
if (hz < 600000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 328 kHz
} else if ((hz >= 600000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 656 kHz
} else if ((hz >= 1000000) && (hz < 2000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.31 MHz
} else if ((hz >= 2000000) && (hz < 5000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2.63 MHz
} else if ((hz >= 5000000) && (hz < 10000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 5.25 MHz
} else if ((hz >= 10000000) && (hz < 20000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 10.5 MHz
} else if ((hz >= 20000000) && (hz < 40000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 21 MHz
} else { // >= 40000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 42 MHz
}
}
// Values depend of PCLK1: 42 MHz
if ((obj->spi == SPI_2) || (obj->spi == SPI_3)) {
if (hz < 300000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 164 kHz
} else if ((hz >= 300000) && (hz < 600000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 328 kHz
} else if ((hz >= 600000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 656 kHz
} else if ((hz >= 1000000) && (hz < 2000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.31 MHz
} else if ((hz >= 2000000) && (hz < 5000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2.63 MHz
} else if ((hz >= 5000000) && (hz < 10000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 5.25 MHz
} else if ((hz >= 10000000) && (hz < 20000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 10.5 MHz
} else { // >= 20000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 21 MHz
}
}
#elif defined(TARGET_STM32F410RB)
// Values depend of PCLK2: 100 MHz
if ((obj->spi == SPI_1) || (obj->spi == SPI_5)) {
if (hz < 700000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 391 kHz
} else if ((hz >= 700000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 781 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.56 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 3.13 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 6.25 MHz
} else if ((hz >= 12000000) && (hz < 25000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 12.5 MHz
} else if ((hz >= 25000000) && (hz < 50000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 25 MHz
} else { // >= 50000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 50 MHz
}
}
// Values depend of PCLK1: 50 MHz
if (obj->spi == SPI_2) {
if (hz < 400000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 195 kHz
} else if ((hz >= 400000) && (hz < 700000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 391 kHz
} else if ((hz >= 700000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 781 MHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.56 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3.13 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6.25 MHz
} else if ((hz >= 12000000) && (hz < 25000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 12.5 MHz
} else { // >= 25000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 25 MHz
}
}
#endif #endif
#if defined SPI5_BASE
case SPI_5:
#endif
#if defined SPI6_BASE
case SPI_6:
#endif
/* SPI_1, SPI_4, SPI_5 and SPI_6. Source CLK is PCKL2 */
spi_hz = HAL_RCC_GetPCLK2Freq();
break;
case SPI_2:
#if defined SPI3_BASE
case SPI_3:
#endif
/* SPI_2 and SPI_3. Source CLK is PCKL1 */
spi_hz = HAL_RCC_GetPCLK1Freq();
break;
default:
error("SPI instance not set");
}
/* Define pre-scaler in order to get highest available frequency below requested frequency */
while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
spi_hz = spi_hz / 2;
prescaler_rank++;
}
if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
} else {
error("Couldn't setup requested SPI frequency");
}
init_spi(obj); init_spi(obj);
} }

89
hal/targets/hal/TARGET_STM/TARGET_STM32F7/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -212,58 +213,50 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
// The frequencies are obtained with: int spi_hz = 0;
// - SPI2/SPI3 clock = 54 MHz (APB1 clock) uint8_t prescaler_rank = 0;
// - SPI1/SPI4/SPI5/SPI6 clocks = 108 MHz (APB2 clock)
switch(obj->spi) { /* Get source clock depending on SPI instance */
case SPI_1: switch ((int)obj->spi) {
case SPI_4: case SPI_1:
case SPI_5: case SPI_4:
case SPI_6: case SPI_5:
if (hz < 800000) { case SPI_6:
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 422 kHz /* SPI_1, SPI_4, SPI_5 and SPI_6. Source CLK is PCKL2 */
} else if ((hz >= 800000) && (hz < 1000000)) { spi_hz = HAL_RCC_GetPCLK2Freq();
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 844 kHz break;
} else if ((hz >= 1000000) && (hz < 3000000)) { case SPI_2:
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.69 MHz case SPI_3:
} else if ((hz >= 3000000) && (hz < 6000000)) { /* SPI_2 and SPI_3. Source CLK is PCKL1 */
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 3.38 MHz spi_hz = HAL_RCC_GetPCLK1Freq();
} else if ((hz >= 6000000) && (hz < 12000000)) { break;
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 6.75 MHz default:
} else if ((hz >= 12000000) && (hz < 24000000)) { error("SPI instance not set");
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 13.5 MHz
} else if ((hz >= 24000000) && (hz < 54000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 27 MHz
} else { // >= 54000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 54 MHz
}
break;
case SPI_2:
case SPI_3:
if (hz < 400000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 211 kHz
} else if ((hz >= 400000) && (hz < 800000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 422 kHz
} else if ((hz >= 800000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 844 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.69 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3.38 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6.75 MHz
} else if ((hz >= 12000000) && (hz < 24000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 13.5 MHz
} else { // >= 24000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 27 MHz
}
break;
default:
return;
} }
/* Define pre-scaler in order to get highest available frequency below requested frequency */
while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
spi_hz = spi_hz / 2;
prescaler_rank++;
}
if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
} else {
error("Couldn't setup requested SPI frequency");
}
init_spi(obj); init_spi(obj);
} }

56
hal/targets/hal/TARGET_STM/TARGET_STM32L0/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -176,27 +177,48 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
// Note: The frequencies are obtained with SPI1 clock = 32 MHz (APB2 clock) int spi_hz = 0;
if (hz < 250000) { uint8_t prescaler_rank = 0;
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz
} else if ((hz >= 250000) && (hz < 500000)) { /* Get source clock depending on SPI instance */
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz switch ((int)obj->spi) {
} else if ((hz >= 500000) && (hz < 1000000)) { case SPI_1:
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz /* SPI_1. Source CLK is PCKL2 */
} else if ((hz >= 1000000) && (hz < 2000000)) { spi_hz = HAL_RCC_GetPCLK2Freq();
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz break;
} else if ((hz >= 2000000) && (hz < 4000000)) { #if defined(SPI2_BASE)
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz case SPI_2:
} else if ((hz >= 4000000) && (hz < 8000000)) { /* SPI_2. Source CLK is PCKL1 */
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz spi_hz = HAL_RCC_GetPCLK1Freq();
} else if ((hz >= 8000000) && (hz < 16000000)) { break;
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz #endif
} else { // >= 16000000 default:
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz error("SPI instance not set");
} }
/* Define pre-scaler in order to get highest available frequency below requested frequency */
while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
spi_hz = spi_hz / 2;
prescaler_rank++;
}
if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
} else {
error("Couldn't setup requested SPI frequency");
}
init_spi(obj); init_spi(obj);
} }

76
hal/targets/hal/TARGET_STM/TARGET_STM32L1/spi_api.c
View File

@ -28,6 +28,7 @@
******************************************************************************* *******************************************************************************
*/ */
#include "mbed_assert.h" #include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h" #include "spi_api.h"
#if DEVICE_SPI #if DEVICE_SPI
@ -177,46 +178,47 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
// Values depend of PCLK1 and PCLK2: 32 MHz if HSI is used, 24 MHz if HSE is used int spi_hz = 0;
if (SystemCoreClock == 32000000) { // HSI uint8_t prescaler_rank = 0;
if (hz < 250000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz /* Get source clock depending on SPI instance */
} else if ((hz >= 250000) && (hz < 500000)) { switch ((int)obj->spi) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz case SPI_1:
} else if ((hz >= 500000) && (hz < 1000000)) { /* SPI_1. Source CLK is PCKL2 */
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz spi_hz = HAL_RCC_GetPCLK2Freq();
} else if ((hz >= 1000000) && (hz < 2000000)) { break;
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz case SPI_2:
} else if ((hz >= 2000000) && (hz < 4000000)) { case SPI_3:
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz /* SPI_2, SPI_3. Source CLK is PCKL1 */
} else if ((hz >= 4000000) && (hz < 8000000)) { spi_hz = HAL_RCC_GetPCLK1Freq();
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz break;
} else if ((hz >= 8000000) && (hz < 16000000)) { default:
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz error("SPI instance not set");
} else { // >= 16000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz
}
} else { // 24 MHz - HSE
if (hz < 180000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 94 kHz
} else if ((hz >= 180000) && (hz < 350000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 188 kHz
} else if ((hz >= 350000) && (hz < 750000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 375 kHz
} else if ((hz >= 750000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 750 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 1.5 MHz
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 3 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 6 MHz
} else { // >= 12000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 12 MHz
}
} }
/* Define pre-scaler in order to get highest available frequency below requested frequency */
while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
spi_hz = spi_hz / 2;
prescaler_rank++;
}
if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
} else {
error("Couldn't setup requested SPI frequency");
}
init_spi(obj); init_spi(obj);
} }

74
hal/targets/hal/TARGET_STM/TARGET_STM32L4/spi_api.c
View File

@ -187,47 +187,47 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
init_spi(obj); init_spi(obj);
} }
static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
SPI_BAUDRATEPRESCALER_4,
SPI_BAUDRATEPRESCALER_8,
SPI_BAUDRATEPRESCALER_16,
SPI_BAUDRATEPRESCALER_32,
SPI_BAUDRATEPRESCALER_64,
SPI_BAUDRATEPRESCALER_128,
SPI_BAUDRATEPRESCALER_256};
void spi_frequency(spi_t *obj, int hz) void spi_frequency(spi_t *obj, int hz)
{ {
// Values depend of PCLK1 and PCLK2: 80 MHz if MSI or HSI is used, 48 MHz if HSE is used int spi_hz = 0;
if (SystemCoreClock == 80000000) { // MSI or HSI uint8_t prescaler_rank = 0;
if (hz < 600000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 313 kHz /* Get source clock depending on SPI instance */
} else if ((hz >= 600000) && (hz < 1000000)) { switch ((int)obj->spi) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 625 kHz case SPI_1:
} else if ((hz >= 1000000) && (hz < 2000000)) { /* SPI_1. Source CLK is PCKL2 */
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1.25 MHz (default) spi_hz = HAL_RCC_GetPCLK2Freq();
} else if ((hz >= 2000000) && (hz < 5000000)) { break;
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2.5 MHz case SPI_2:
} else if ((hz >= 5000000) && (hz < 10000000)) { case SPI_3:
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 5 MHz /* SPI_2, SPI_3. Source CLK is PCKL1 */
} else if ((hz >= 10000000) && (hz < 20000000)) { spi_hz = HAL_RCC_GetPCLK1Freq();
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 10 MHz break;
} else if ((hz >= 20000000) && (hz < 40000000)) { default:
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 20 MHz error("SPI instance not set");
} else { // >= 40000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 40 MHz
}
} else { // 48 MHz - HSE
if (hz < 350000) {
obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 188 kHz
} else if ((hz >= 350000) && (hz < 750000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 375 kHz
} else if ((hz >= 750000) && (hz < 1000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 750 kHz
} else if ((hz >= 1000000) && (hz < 3000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1.5 MHz (default)
} else if ((hz >= 3000000) && (hz < 6000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 3 MHz
} else if ((hz >= 6000000) && (hz < 12000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 6 MHz
} else if ((hz >= 12000000) && (hz < 24000000)) {
obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 12 MHz
} else { // >= 24000000
obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 24 MHz
}
} }
/* Define pre-scaler in order to get highest available frequency below requested frequency */
while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
spi_hz = spi_hz / 2;
prescaler_rank++;
}
if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
} else {
error("Couldn't setup requested SPI frequency");
}
init_spi(obj); init_spi(obj);
} }