4.12.1 I2C Control
SDA is a bidirectional data line. Data is clocked into and out of the part by the clock, SCL. The signal tim-
ings for a read and write cycle are shown in Figure 20 and Figure 21. A Start condition is defined as a
falling transition of SDA while the clock is high. A Stop condition is defined as a rising transition of SDA
while the clock is high. All other transitions of SDA occur while the clock is low. The first byte sent to the
CS42L52 after a Start condition consists of a 7-bit chip address field and a R/W bit (high for a read, low
for a write).
The upper 7 bits of the address field are fixed at 1001010. To communicate with the CS42L52, the chip
address field, which is the first byte sent to the CS42L52, should match 1001010. The eighth bit of the
address is the R/W bit. If the operation is a write, the next byte is the Memory Address Pointer (MAP),
which selects the register to be read or written. If the operation is a read, the contents of the register point-
ed to by the MAP will be output. Setting the auto-increment bit in MAP allows successive reads or writes
of consecutive registers. Each byte is separated by an acknowledge bit. The ACK bit is output from the
CS42L52 after each input byte is read and is input to the CS42L52 from the microcontroller after each
transmitted byte.