dataflash.c

/* This file is part of ukbdc.
 *
 * ukbdc 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 2 of the License, or
 * (at your option) any later version.
 *
 * ukbdc 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 ukbdc; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "platforms.h"
#include "dataflash.h"

#include <util/delay.h>

void DATAFLASH_send_byte(uint8_t byte)
{
	for (uint8_t mask = (1 << 7); mask != 0; mask >>= 1) {
		if (byte & mask)
			DATAFLASH_SI_HIGH();
		else
			DATAFLASH_SI_LOW();
		/* send bit */
		DATAFLASH_CLK_HIGH();
		DATAFLASH_CLK_LOW();
	}
}

uint8_t DATAFLASH_recv_byte()
{
	uint8_t byte = 0;
	for (uint8_t i = 0; i < 8; ++i) {
		byte <<= 1;
		byte |= DATAFLASH_SO_STATE();
		/* get next bit */
		DATAFLASH_CLK_HIGH();
		DATAFLASH_CLK_LOW();
	}
	return byte;
}

uint8_t DATAFLASH_status()
{
	DATAFLASH_CS_SET();
	DATAFLASH_send_byte(STATUS_REGISTER_READ);
	uint8_t status = DATAFLASH_recv_byte();
	DATAFLASH_CS_CLEAR();
	return status;
}

void DATAFLASH_write_page(uint16_t page_addr, uint16_t size, const uint8_t *buffer)
{
	DATAFLASH_CS_SET();
	DATAFLASH_send_byte(PROGRAM_THROUGH_BUFFER);
	DATAFLASH_send_byte((uint8_t)(page_addr >> 6));
	DATAFLASH_send_byte((uint8_t)(page_addr << 2));
	DATAFLASH_send_byte(0x00);
	for (uint16_t i = 0; i < size; ++i)
		DATAFLASH_send_byte(buffer[i]);
	DATAFLASH_CS_CLEAR();
}

void DATAFLASH_read_page(uint16_t page_addr, uint16_t size, uint8_t *buffer)
{
	DATAFLASH_CS_SET();
	DATAFLASH_send_byte(CONTINUOUS_ARRAY_READ_LOW);
	DATAFLASH_send_byte((uint8_t)(page_addr >> 6));
	DATAFLASH_send_byte((uint8_t)(page_addr << 2));
	DATAFLASH_send_byte(0x00);
	for (uint16_t i = 0; i < size; ++i)
		buffer[i] = DATAFLASH_recv_byte();
	DATAFLASH_CS_CLEAR();
}