Data Sheet

Page 26 ams Datasheet
Document Feedback [v1-04] 2018-Jul-09
AS7265x − Detailed Description
I²C Virtual Register Byte Read, detailed below, shows the
pseudocode necessary to read virtual registers on the AS72651.
Note that in this case, reading a virtual register, the register
address is not modified.
I²C Virtual Register Byte Read
Pseudocode
Poll I²C slave STATUS register;
If TX_VALID bit is 0, the virtual register address for the read may be written;
Send a virtual register address;
Poll I²C slave STATUS register;
If RX_VALID bit is 1, the read data is ready;
Read the data.
Sample Code
uint8_t i2cm_AS72xx_read(uint8_t virtualReg)
{
volatile uint8_t status, d;
while (1)
{
// Read slave I²C status to see if the read 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 (disabling bit 7 to indicate a read).
i2cm_write(I2C_AS72XX_SLAVE_WRITE_REG, virtualReg);
while (1)
{
// Read the slave I²C status to see if our read data is available.
status = i2cm_read(I2C_AS72XX_SLAVE_STATUS_REG);
if ((status & I2C_AS72XX_SLAVE_RX_VALID)!= 0)
// Read data is ready.
break;
}
// Read the data to complete the operation.
d = i2cm_read(I2C_AS72XX_SLAVE_READ_REG) ;
return d;s
}
The details of the i2cm_read() and i2cm_write() functions in
previous figures are dependent upon the nature and implemen-
tation of the external I²C master device.