Electronics America 8-Bit Single-Chip Microcontrollers User's Manual

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CHAPTER 17 SERIAL INTERFACE CHANNEL 0 ( µ PD78054Y Subseries)
(4) I
2
C (Inter IC) bus mode (MSB-first)
This mode is used for 8-bit data transfer with two or more devices using two lines of serial clock (SCL) and
serial data bus (SDA0 or SDA1).
This mode is in compliance with the I
2
C bus format. In this mode, the transmitter can output three kinds of
data onto the serial data bus: “start condition”, “data”, and “stop condition”, to be actually sent or received.
The receiver automatically distinguishes the received data into “start condition”, “data”, or “stop condition”,
by hardware.
Figure 17-1. Serial Bus Configuration Example Using I
2
C Bus
Master CPU
SCL
SDA0 (SDA1)
SCL
SDA0 (SDA1)
Slave CPU1
Slave CPU2
Slave CPUn
V DD
V DD
SCL
SDA0 (SDA1)
SCL
SDA0 (SDA1)