/* receives a character from I2C rountine.
*
* @return value: character received
*
*/
static unsigned char i2c_receive_byte(void)
{
int j=0;
int i;
unsigned char regvalue;
local_irq_disable();
for (i=0; i<8; i++)
{
DELAY(1);
i2c_clr(SCL);
DELAY(1);
i2c_set(SCL);
regvalue = HW_REG(GPIO_0_DIR);
regvalue &= (~SDA);
HW_REG(GPIO_0_DIR) = regvalue;
DELAY(1);
if (i2c_data_read())
j+=(1<<(7-i));
DELAY(1);
i2c_clr(SCL);
}
local_irq_enable();
DELAY(1);
// i2c_clr(SDA);
// DELAY(1);
return j;
}
/* receives an acknowledge from I2C rountine.
*
* @return value: 0--Ack received; 1--Nack received
*
*/
static int i2c_receive_ack(void)
{
int nack;
unsigned char regvalue;
DELAY(1);
regvalue = HW_REG(GPIO_0_DIR);
regvalue &= (~SDA);
HW_REG(GPIO_0_DIR) = regvalue;
DELAY(1);
i2c_clr(SCL);
DELAY(1);
i2c_set(SCL);
DELAY(1);
nack = i2c_data_read();
DELAY(1);
i2c_clr(SCL);
DELAY(1);
// i2c_set(SDA);
// DELAY(1);
if (nack == 0)
return 1;
return 0;
}
static int i2c_receive_ack(int Grp)
{
int nack;
unsigned char regvalue;
DELAY(1);
regvalue = HW_REG(GPIO_I2C_DIR[Grp]);
regvalue &= (~GPIO_I2C_BIT[Grp][PINI2C_SDA]);
HW_REG(GPIO_I2C_DIR[Grp]) = regvalue;
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
DELAY(1);
i2c_set(Grp, PINI2C_SCL);
DELAY(1);
nack = i2c_data_read(Grp);
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
DELAY(1);
return !nack;
}
static unsigned char i2c_receive_byte(int Grp)
{
int j = 0;
int i;
unsigned char regvalue;
local_irq_disable();
for (i = 0; i < 8; i ++) {
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
DELAY(2);
i2c_set(Grp, PINI2C_SCL);
regvalue = HW_REG(GPIO_I2C_DIR[Grp]);
regvalue &= (~GPIO_I2C_BIT[Grp][PINI2C_SDA]);
HW_REG(GPIO_I2C_DIR[Grp]) = regvalue;
DELAY(1);
if (i2c_data_read(Grp)) {
j+=(1<<(7-i));
}
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
}
local_irq_enable();
DELAY(1);
return j;
}
static void i2c_send_byte(int Grp, unsigned char c)
{
int i;
local_irq_disable();
for (i = 0; i < 8; i ++) {
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
DELAY(1);
if (c & (1<<(7-i)))
i2c_set(Grp, PINI2C_SDA);
else
i2c_clr(Grp, PINI2C_SDA);
DELAY(1);
i2c_set(Grp, PINI2C_SCL);
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
}
local_irq_enable();
DELAY(1);
}
static void i2c_send_ack(void)
{
DELAY(1);
i2c_clr(SCL);
DELAY(1);
i2c_set(SDA);
DELAY(1);
i2c_set(SCL);
DELAY(1);
i2c_clr(SCL);
DELAY(1);
i2c_clr(SDA);
DELAY(1);
}
/*
* sends a stop bit via I2C rountine.
*
*/
static void i2c_stop_bit(void)
{
/* clock the ack */
DELAY(1);
i2c_set(SCL);
DELAY(1);
i2c_clr(SCL);
/* actual stop bit */
DELAY(1);
i2c_clr(SDA);
DELAY(1);
i2c_set(SCL);
DELAY(1);
i2c_set(SDA);
DELAY(1);
}
/*
* sends a start bit via I2C rountine.
*
*/
static void i2c_start_bit(void)
{
DELAY(1);
i2c_set(SDA | SCL);
DELAY(1);
i2c_clr(SDA);
DELAY(1);
}
static void i2c_send_ack(int Grp)
{
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
DELAY(1);
i2c_set(Grp, PINI2C_SDA);
DELAY(1);
i2c_set(Grp, PINI2C_SCL);
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
DELAY(1);
i2c_clr(Grp, PINI2C_SDA);
DELAY(1);
}
static void i2c_start_bit(int Grp)
{
DELAY(1);
i2c_set(Grp, PINI2C_DAT);
DELAY(1);
i2c_clr(Grp, PINI2C_SDA);
DELAY(2);
}
static void i2c_stop_bit(int Grp)
{
/* clock the ack */
DELAY(1);
i2c_set(Grp, PINI2C_SCL);
DELAY(1);
i2c_clr(Grp, PINI2C_SCL);
/* actual stop bit */
DELAY(1);
i2c_clr(Grp, PINI2C_SDA);
DELAY(1);
i2c_set(Grp, PINI2C_SCL);
DELAY(1);
i2c_set(Grp, PINI2C_SDA);
DELAY(1);
}
/*
* sends a character over I2C rountine.
*
* @param c: character to send
*
*/
static void i2c_send_byte(unsigned char c)
{
int i;
local_irq_disable();
for (i=0; i<8; i++)
{
DELAY(1);
i2c_clr(SCL);
DELAY(1);
if (c & (1<<(7-i)))
i2c_set(SDA);
else
i2c_clr(SDA);
DELAY(1);
i2c_set(SCL);
DELAY(1);
i2c_clr(SCL);
}
DELAY(1);
// i2c_set(SDA);
local_irq_enable();
}
