ams Datasheet

Page 19

[v1-00] 2016-Dec-16

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AS7262 − Detailed Description

I²C Virtual Register Byte Write

Pseudocode

Poll I²C slave STATUS register;

If TX_VALID bit is 0, a write can be performed on the interface;

Send a virtual register address and set the MSB of the register address to 1 to indicate the pending write;

Poll I²C slave STATUS register;

If TX_VALID bit is 0, the virtual register address for the write has been received and the data may now be written;

Write the data.

Sample Code:

#define I2C_AS72XX_SLAVE_STATUS_REG

0x00

#define I2C_AS72XX_SLAVE_WRITE_REG

0x01

#define I2C_AS72XX_SLAVE_READ_REG

0x02

#define I2C_AS72XX_SLAVE_TX_VALID

0x02

#define I2C_AS72XX_SLAVE_RX_VALID

0x01

void i2cm_AS72xx_write(uint8_t virtualReg, uint8_t d)

{

volatile uint8_t

status;

while (1)

{

// Read slave I²C status to see if the write buffer is ready.

status = i2cm_read(I2C_AS72XX_SLAVE_STATUS_REG);

if ((status & I2C_AS72XX_SLAVE_TX_VALID) == 0)

// No inbound TX pending at slave. Okay to write now.

break;

}

// Send the virtual register address (setting bit 7 to indicate a pending write).

i2cm_write(I2C_AS72XX_SLAVE_WRITE_REG, (virtualReg | 0x80));

while (1)

{

// Read the slave I²C status to see if the write buffer is ready.

status = i2cm_read(I2C_AS72XX_SLAVE_STATUS_REG);

if ((status & I2C_AS72XX_SLAVE_TX_VALID) == 0)

// No inbound TX pending at slave. Okay to write data now.

break;

}

// Send the data to complete the operation.

i2cm_write(I2C_AS72XX_SLAVE_WRITE_REG, d);

}