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fpgaspi_program.c
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fpgaspi_program.c
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/*
Xilinx Spartan 6 FPGA Programming Routines
Copyright (c) 2014-2015 NewAE Technology Inc. All rights reserved.
Author: Colin O'Flynn, <coflynn@newae.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <asf.h>
#include "gpio.h"
#include "fpgaspi_program.h"
#include "spi.h"
/* FPGA Programming: Init pins - assumes FPGA already programmed to use these */
void fpgaspi_program_init(void)
{
FPGASPI_CCLK_SETUP();
FPGASPI_DO_SETUP();
FPGASPI_DI_SETUP();
FPGASPI_CS_SETUP();
FPGASPI_CS_HIGH();
FPGASPI_CCLK_LOW();
}
/* SPI CS Pin Low */
void fpgaspi_cs_low(void)
{
FPGASPI_CS_LOW();
}
/* SPI CS Pin High */
void fpgaspi_cs_high(void)
{
FPGASPI_CS_HIGH();
}
/* SPI data byte transfer */
uint8_t fpgaspi_xferbyte(uint8_t databyte)
{
uint8_t result = 0;
for(unsigned int i=0; i < 8; i++){
//On first read this gets thrown away
result |= FPGASPI_DI_STATUS() ? (1) : 0;
FPGASPI_CCLK_LOW();
if (databyte & 0x80){
FPGASPI_DO_HIGH();
} else {
FPGASPI_DO_LOW();
}
FPGASPI_CCLK_HIGH();
databyte = databyte << 1;
result = result << 1;
}
result |= FPGASPI_DI_STATUS() ? (1) : 0;
FPGASPI_CCLK_LOW();
return result;
}
void fpgaspi_program_deinit(void)
{
FPGASPI_CCLK_RELEASE();
FPGASPI_DO_RELEASE();
FPGASPI_CS_RELEASE();
}