From 2eea25873dbc2bc57aa9f6ff6f2c74f2eff855f2 Mon Sep 17 00:00:00 2001 From: Markus Sattler Date: Fri, 15 May 2015 13:42:30 +0200 Subject: [PATCH] fix SPI speed calculation @160Mhz Clock --- libraries/SPI/SPI.cpp | 6 +++--- libraries/SPI/SPI.h | 2 ++ 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/libraries/SPI/SPI.cpp b/libraries/SPI/SPI.cpp index c96c4fcb8..7d52528ef 100644 --- a/libraries/SPI/SPI.cpp +++ b/libraries/SPI/SPI.cpp @@ -121,14 +121,14 @@ void SPIClass::setBitOrder(uint8_t bitOrder) { * @return */ static uint32_t ClkRegToFreq(spiClk_t * reg) { - return (F_CPU / ((reg->regPre + 1) * (reg->regN + 1))); + return (SPI_MAX_SPEED / ((reg->regPre + 1) * (reg->regN + 1))); } void SPIClass::setFrequency(uint32_t freq) { static uint32_t lastSetFrequency = 0; static uint32_t lastSetRegister = 0; - if(freq >= F_CPU) { + if(freq >= SPI_MAX_SPEED) { setClockDivider(0x80000000); return; } @@ -164,7 +164,7 @@ void SPIClass::setFrequency(uint32_t freq) { reg.regN = calN; while(calPreVari++ <= 1) { // test different variants for Pre (we calculate in int so we miss the decimals, testing is the easyest and fastest way) - calPre = (((F_CPU / (reg.regN + 1)) / freq) - 1) + calPreVari; + calPre = (((SPI_MAX_SPEED / (reg.regN + 1)) / freq) - 1) + calPreVari; if(calPre > 0x1FFF) { reg.regPre = 0x1FFF; // 8191 } else if(calPre <= 0) { diff --git a/libraries/SPI/SPI.h b/libraries/SPI/SPI.h index e67b5b0d5..68d2a3dc6 100644 --- a/libraries/SPI/SPI.h +++ b/libraries/SPI/SPI.h @@ -45,6 +45,8 @@ #define SPI_CLOCK_DIV64 0x04fc1001 //250 KHz #endif +#define SPI_MAX_SPEED (80000000L) + const uint8_t SPI_MODE0 = 0x00; ///< CPOL: 0 CPHA: 0 const uint8_t SPI_MODE1 = 0x01; ///< CPOL: 0 CPHA: 1 const uint8_t SPI_MODE2 = 0x10; ///< CPOL: 1 CPHA: 0