i2c_sbl.c

LPC2102的keil vendor code

/*****************************************************************************
 *   i2c_sbl.c:  I2C_SBL API file for NXP LPC210x Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2005.10.01  ver 1.00    Prelimnary version, first Release
******************************************************************************/

#include "LPC210x.H"
#include "i2c_sbl.h"
#include "i2c.h"

extern unsigned int data_block_cnt;

/*****************************************************************************
** Function name:	i2c_sbl_init
** Description:		This function initializes the I2C data and clock bus
** Parameter:		None
** Returned value:	None
*****************************************************************************/
void i2c_sbl_init(void)
{
	PINSEL0 |= 0x00000050;		// Set P0.2 as SCL0 and P0.3 as SDA0

	/*--- Clear flags ---*/
	I2C0CONCLR = I2CONCLR_AAC | I2CONCLR_SIC | I2CONCLR_STAC | I2CONCLR_I2ENC;    

	I2C0SCLL = I2SCLL_SCLL;
	I2C0SCLH = I2SCLH_SCLH;

	I2C0ADR = I2CSL_ADDRS << 1;

	I2C0CONSET = I2CONSET_I2EN | I2CONSET_AA;
} // i2c_sbl_init

/*****************************************************************************
** Function name:	i2c0_readbyte
** Description:		This function reads data from the I2C data register
** Parameter:		None
** Returned value:	I2C data byte
*****************************************************************************/
unsigned char i2c0_readbyte(void)
{
	unsigned char databyte;
	
	while( !(I2C0CONSET & I2CONSET_SI) );
	while( (!(I2C0STAT & 0x80)) && (!(I2C0STAT & 0x90)) );
	databyte = I2C0DAT;          // read data	
	I2C0CONCLR = I2CONSET_SI;
	
	return (databyte);
} // i2c0_readbyte

/*****************************************************************************
** Function name:	i2c0_writebyte
** Description:		This function writes data to the I2C data register
** Parameter:		I2C data byte
** Returned value:	None
*****************************************************************************/
void i2c0_writebyte(unsigned char databyte)
{
	while( !(I2C0CONSET & I2CONSET_SI) );
	while ((!(I2C0STAT & 0xA8))&&(!(I2C0STAT & 0xB8))&&(!(I2C0STAT & 0xC8)));
	I2C0DAT = databyte;          // write data	
	I2C0CONCLR = I2CONSET_SI;
	return;
} // i2c0_writebyte

/*****************************************************************************
** Function name:	i2c0_ready
** Description:		This function enables I2C interface and setup ACK to 
**					return acknowledge when the address in the Slave Address
**					register has been received.
** Parameter:		None
** Returned value:	None
*****************************************************************************/
void i2c0_ready(void)
{
	I2C0ADR = I2CSL_ADDRS << 1;
	I2C0CONSET = (I2CONSET_I2EN | I2CONSET_AA);
} // i2c0_ready

/*****************************************************************************
** Function name:	slave_receive
** Description:		The order of the slave receive is:
**              	1. I2C Slave Device Addr: 0x2E
**					2. Command ID: 0x02
**					3. Block number (MSB)
**					4. Block number (LSB)
**
**              	If both MSB and LSB of block numbers are zero, get the 
**					checksum. Otherwise, get 1024 bytes of data.
** Parameter:		I2C slave buffer
** Returned value:	status of slave_receive
*****************************************************************************/
unsigned int slave_receive( unsigned char slave_buffer[] )
{
	unsigned char cmdbyte, paraMSB, paraLSB, databyte, checksumbyte;
	unsigned char checksum = 0;
	unsigned int i;
	
	i2c_sbl_init();
	
	i2c0_ready();
	while( !(I2C0CONSET & I2CONSET_SI) );
	// neither I2C Read bit set, nor arbitration loss, start of slave receive
	while(((I2C0STAT & 0x60)==0)&&((I2C0STAT & 0x68)==0));
	I2C0CONSET = I2CONSET_AA;	// Return ACK on first byte
	I2C0CONCLR = I2CONSET_SI;
	
	/* 2. Command ID handling */
	cmdbyte = i2c0_readbyte();
	checksum -= cmdbyte;
	if( cmdbyte == 0x02 )	// Command byte
	{
		I2C0CONSET = I2CONSET_AA;	// Return ACK on DATA byte
	}
	else
	{
		/* This case is not handled in main(), please take note */
		I2C0CONCLR = I2CONSET_AA;	// BAD command, return NACK on DATA byte
		return( COMMAND_BAD );
	}
	
	/* 3. Block number (MSB) */
	paraMSB = i2c0_readbyte();	// Read data
	checksum -= paraMSB;
	I2C0CONSET = I2CONSET_AA;	// Return ACK on DATA byte
	
	/* 4. Block number (LSB) */
	paraLSB = i2c0_readbyte();  // Read data
	checksum -= paraLSB;
	
	if( paraMSB == 0x00 && paraLSB == 0x00 )
	{
		checksumbyte = i2c0_readbyte();	// Receive checksum data
		if( checksum != checksumbyte )	// Check checksum of command ID and block number (MSB & LSB)
		{
			I2C0CONCLR = I2CONSET_AA;	// Return NACK on data byte
			return CHECKSUM_BAD;
		}

		I2C0CONSET = I2CONSET_AA;	// Return ACK on data byte
		return( DONE );
	}
	else
	{
		I2C0CONSET = I2CONSET_AA;	// Return ACK on data byte
	}
	
	/* Save global varaible for block number */
	data_block_cnt = (paraMSB << 8) | paraLSB;
	
	for(i = 0; i < 1024; i++)
	{
		while( !(I2C0CONSET & I2CONSET_SI) );
		if( (I2C0STAT == 0xA0) && (i<1023) )	// STOP occurs before completion
		{
			I2C0CONCLR = I2CONSET_SI;
			I2C0CONCLR = I2CONSET_AA;	// Return NACK on data byte
			return( DATA_BAD );
		}
		else
		{
			databyte = i2c0_readbyte();	// Receive data	from the I2C data register
			slave_buffer[i] = databyte; // Store data in slave buffer
			checksum -= databyte;		// Add data to the checksum
			I2C0CONSET = I2CONSET_AA;	// Return ACK on data byte
		}
	}
	
	checksumbyte = i2c0_readbyte(); // Receive checksum data
	if (checksum != checksumbyte)   // Check checksum of command ID, block number (MSB and LSB) and received data
	{
		I2C0CONCLR = I2CONSET_AA;	// Return NACK on data byte
		return CHECKSUM_BAD;
	}
	I2C0CONSET = I2CONSET_AA;	// Return ACK on data byte
	
	return(DATA_OK);
} // slave_receive

/*****************************************************************************
** Function name:	slave_transmit
** Description:		The function sends thrice the status of the SBL:
**              	'0x00' - Programming success
**					'0xFF' - Programming failure
** Parameter:		SBL status byte
** Returned value:	None
*****************************************************************************/
void slave_transmit( unsigned char statusbyte )
{
	I2C0CONCLR = I2CONSET_SI;
	i2c0_ready();
	
	i2c0_writebyte(statusbyte);
	I2C0CONSET = I2CONSET_AA;
	i2c0_writebyte(statusbyte);
	I2C0CONSET = I2CONSET_AA;
	i2c0_writebyte(statusbyte);
	I2C0CONCLR = I2CONSET_AA;
	return;
} // slave_transmit