Samsung SC32442B54, User Manual

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IIC-BUS INTERFACE SC32442B RISC MICROPROCESSOR
20-4
DATA TRANSFER FORMAT
Every byte placed on the SDA line should be eight bits in length. The bytes can be unlimitedly transmitted per
transfer. The first byte following a Start condition should have the address field. The address field can be
transmitted by the master when the IIC-bus is operating in Master mode. Each byte should be followed by an
acknowledgement (ACK) bit. The MSB bit of the serial data and addresses are always sent first.
Figure 20-3. IIC-Bus Interface Data Format
SDA
Acknowledgement
Signal from Receiver
SCL
S
1 2 7 8 9 1 2 9
Acknowledgement
Signal from Receiver MSB
ACK
Byte Complete, Interrupt
within Receiver
Clock Line Held Low by
receiver and/or transmitter
Figure 20-4. Data Transfer on the IIC-Bus
ACK SIGNAL TRANSMISSION
To complete a one-byte transfer operation, the receiver should send an ACK bit to the transmitter. The ACK pulse
should occur at the ninth clock of the SCL line. Eight clocks are required for the one-byte data transfer. The master
should generate the clock pulse required to transmit the ACK bit.
The transmitter should release the SDA line by making the SDA line High when the ACK clock pulse is received.