WebSVN - idreammicro-avr - Blame - Rev 55 - /trunk/libraries/eeprom_24c512/src/eeprom

Rev	Author	Line No.	Line
45	jlesech	1	/************************************************************************//
		2	* \brief EEPROM 24C512 library.
		3	* \author Copyright (C) 2012 Julien Le Sech - www.idreammicro.com
		4	* \version 1.0
		5	* \date 20121031
		6	*
		7	* This file is part of the iDreamMicro library.
		8	*
		9	* This library is free software: you can redistribute it and/or modify it under
		10	* the terms of the GNU Lesser General Public License as published by the Free
		11	* Software Foundation, either version 3 of the License, or (at your option) any
		12	* later version.
		13	*
		14	* This library is distributed in the hope that it will be useful, but WITHOUT
		15	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
		16	* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
		17	* details.
		18	*
		19	* You should have received a copy of the GNU Lesser General Public License
		20	* along with this program. If not, see http://www.gnu.org/licenses/
		21	******************************************************************************/
		22
		23	/************************************************************************//
		24	* \file eeprom_24c512.c
		25	******************************************************************************/
		26
		27	/******************************************************************************
		28	* Header file inclusions.
		29	******************************************************************************/
		30
		31	#include "../eeprom_24c512.h"
		32
		33	#include <twi/twi.h>
		34
		35	#include <util/delay.h>
		36
		37	#include <assert.h>
		38	#include <stdint.h>
		39	#include <stdlib.h>
		40
		41	/******************************************************************************
		42	* Private macro definitions.
		43	******************************************************************************/
		44
		45	/************************************************************************//
		46	* \def EEPROM_24C512__ADDRESS
		47	* \brief EEPROM 24C512 address. Given by datasheet.
		48	******************************************************************************/
		49	#define EEPROM_24C512__ADDRESS 0xA0
		50
		51	/************************************************************************//
49	jlesech	52	* \def EEPROM_24C512__PAGE_SIZE
45	jlesech	53	* \brief Size of a page in EEPROM memory.
		54	* This size is given by EEPROM memory datasheet.
		55	******************************************************************************/
		56	#define EEPROM_24C512__PAGE_SIZE 128
		57
		58	/******************************************************************************
		59	* Private function prototypes.
		60	******************************************************************************/
		61
		62	/************************************************************************//
48	jlesech	63	* \fn static void eeprom_24c512__write_page(
		64	* uint16_t address,
		65	* uint8_t length,
		66	* uint8_t* p_data)
45	jlesech	67	*
48	jlesech	68	* \brief Write a page in memory.
		69	*
		70	* \param address Start address of data to write.
		71	* \param length Number of bytes to write.
		72	* \param[in] p_data Bytes to write.
45	jlesech	73	******************************************************************************/
46	jlesech	74	static
45	jlesech	75	void
		76	eeprom_24c512__write_page
		77	(
		78	uint16_t address,
		79	uint8_t length,
		80	uint8_t* p_data
46	jlesech	81	);
45	jlesech	82
		83	/******************************************************************************
		84	* Private variable declarations.
		85	******************************************************************************/
		86
		87	static uint8_t device_address = 0;
		88
		89	/******************************************************************************
		90	* Public function definitions.
		91	******************************************************************************/
		92
		93	/************************************************************************//
		94	* \fn void eeprom_24c512__initialize(uint8_t hardware_address)
		95	*
		96	* \brief Initialize EEPROM 24C512.
		97	*
48	jlesech	98	* \param hardware_address Hardware address. Pins A0 to A1.
45	jlesech	99	******************************************************************************/
		100	void
		101	eeprom_24c512__initialize
		102	(
		103	uint8_t hardware_address
		104	){
		105	// Compute device address.
48	jlesech	106	device_address = EEPROM_24C512__ADDRESS \| ((hardware_address & 0x03) << 1);
45	jlesech	107
		108	// We don't initialize TWI here: we may have several devices on the bus.
		109	// Initialize TWI.
		110	//twi__initialize(EEPROM_24C512__CLOCK_RATE);
		111	}
		112
		113	/************************************************************************//
		114	* \fn void eeprom_24c512__write_byte(uint16_t address, uint8_t data)
		115	*
		116	* \brief Write a byte into memory.
		117	*
		118	* \param address Address in memory.
		119	* \param data Byte to write.
		120	******************************************************************************/
		121	void
		122	eeprom_24c512__write_byte
		123	(
		124	uint16_t address,
		125	uint8_t data
		126	){
		127	twi__start();
		128	twi__send_slaw(device_address);
		129	twi__send_data(address >> 8);
		130	twi__send_data(address & 0xFF);
		131	twi__send_data(data);
		132	twi__stop();
		133	}
		134
		135	/************************************************************************//
		136	* \fn void eeprom_24c512__write_bytes(
		137	* uint16_t address,
		138	* uint16_t length,
		139	* uint8_t* p_data)
		140	*
		141	* \brief Write bytes into memory.
		142	*
		143	* \param address Start address.
		144	* \param length Number of bytes to write.
		145	* \param[in] p_data Bytes to write.
		146	******************************************************************************/
		147	void
		148	eeprom_24c512__write_bytes
		149	(
		150	uint16_t address,
		151	uint16_t length,
		152	uint8_t* p_data
		153	){
		154	// Check the preconditions.
		155	assert(NULL != p_data);
		156
		157	// Write first page if not aligned.
		158	uint8_t not_aligned_length = 0;
		159	uint8_t page_offset = address % EEPROM_24C512__PAGE_SIZE;
		160	if (page_offset > 0)
		161	{
		162	not_aligned_length = EEPROM_24C512__PAGE_SIZE - page_offset;
		163	eeprom_24c512__write_page(address, not_aligned_length, p_data);
		164	length -= not_aligned_length;
		165	}
		166
		167	if (length > 0)
		168	{
		169	address += not_aligned_length;
		170	p_data += not_aligned_length;
		171
		172	// Write complete and aligned pages.
		173	uint16_t page_count = length / EEPROM_24C512__PAGE_SIZE;
		174	for (uint16_t i = 0; i < page_count; i++)
		175	{
		176	eeprom_24c512__write_page(address, EEPROM_24C512__PAGE_SIZE, p_data);
		177	address += EEPROM_24C512__PAGE_SIZE;
		178	p_data += EEPROM_24C512__PAGE_SIZE;
		179	length -= EEPROM_24C512__PAGE_SIZE;
		180	}
		181
		182	if (length > 0)
		183	{
		184	// Write remaining uncomplete page.
55	jlesech	185	eeprom_24c512__write_page(address, length, p_data);
45	jlesech	186	}
		187	}
		188	}
		189
		190	/************************************************************************//
		191	* \fn uint8_t eeprom_24c512__read_byte(uint16_t address)
		192	*
		193	* \brief Read a byte in memory.
		194	*
		195	* \param address Address to read.
		196	*
		197	* \return Read byte.
		198	******************************************************************************/
		199	uint8_t
		200	eeprom_24c512__read_byte
		201	(
		202	uint16_t address
		203	){
		204	uint8_t data = 0;
		205
		206	twi__start();
		207	twi__send_slaw(device_address);
		208	twi__send_data(address >> 8);
		209	twi__send_data(address & 0xFF);
48	jlesech	210	twi__repeat_start();
45	jlesech	211	twi__send_slar(device_address);
		212	twi__receive_data_nack(&data);
		213	twi__stop();
		214
		215	return data;
		216	}
		217
		218	/************************************************************************//
		219	* \fn void eeprom_24c512__read_bytes(
		220	* uint16_t address,
		221	* uint16_t length,
		222	* uint8_t* p_data)
		223	*
		224	* \brief Read bytes in memory.
		225	*
		226	* \param address Start address of data to read.
		227	* \param length Number of bytes to read.
		228	* \param[in] p_data Buffer to fill with read bytes.
		229	******************************************************************************/
		230	void
		231	eeprom_24c512__read_bytes
		232	(
		233	uint16_t address,
		234	uint16_t length,
		235	uint8_t* p_data
		236	){
		237	// Check the preconditions.
		238	assert(NULL != p_data);
		239
		240	twi__start();
		241	twi__send_slaw(device_address);
		242	twi__send_data(address >> 8);
		243	twi__send_data(address & 0xFF);
48	jlesech	244	twi__repeat_start();
45	jlesech	245	twi__send_slar(device_address);
		246	for (uint16_t i = 0; i < length - 1; i++)
		247	{
		248	twi__receive_data_ack(p_data + i);
		249	}
		250	twi__receive_data_nack(p_data + length - 1);
		251	twi__stop();
		252	}
		253
		254	/******************************************************************************
		255	* Private function definitions.
		256	******************************************************************************/
		257
		258	/************************************************************************//
		259	* \fn static void eeprom_24c512__write_page(
		260	* uint16_t address,
		261	* uint8_t length,
		262	* uint8_t* p_data)
		263	*
		264	* \brief Write a page in memory.
		265	*
		266	* \param address Start address of data to write.
		267	* \param length Number of bytes to write.
		268	* \param[in] p_data Bytes to write.
		269	******************************************************************************/
46	jlesech	270	static
45	jlesech	271	void
		272	eeprom_24c512__write_page
		273	(
		274	uint16_t address,
		275	uint8_t length,
		276	uint8_t* p_data
		277	){
		278	// Check the preconditions.
		279	assert(NULL != p_data);
		280
		281	twi__start();
		282	twi__send_slaw(device_address);
		283	twi__send_data(address >> 8);
		284	twi__send_data(address & 0xFF);
		285	for (uint8_t i = 0; i < length; i++)
		286	{
		287	twi__send_data(p_data[i]);
		288	}
		289	twi__stop();
		290
		291	// Write cycle time (tWR). See EEPROM memory datasheet for more details.
		292	_delay_ms(10);
		293	}

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(root)/trunk/libraries/eeprom_24c512/src/eeprom_24c512.c - Rev 55