NEC PD78214 - Manual (Page 426)

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Chapter 16 Application Examples
16
16.2 SERIAL COMMUNICATION WITH MULTIPLE DEVICES
Fig. 16-2 shows an example of a system configured with a serial bus interface. The serial bus interface can transfer
addresses (for selecting devices), commands, and data, as well as acknowledge and busy signals, using only two
lines: The serial clock and serial bus lines.
When a master device communicates with multiple slave devices, the master device outputs an address for
selecting a slave device on the serial bus line. Each slave device checks whether the received address is the same
as the address assigned to the device, using software. Only a slave device whose address is the same as the
received address returns an acknowledge signal to the master device, after which it receives commands from the
master device or transfers data to and from the master device. Fig. 16-3 shows an example of communication
using the serial bus interface (SBI).
Fig. 16-2 Example System Configuration Using the Serial Bus Interface
SCK
SB0
PD78214 µ
SCK
SB0
PD75402 µ
SCK
SB0
PD75008 µ
SCK
SB0
PD75308 µ
[Master] [Slave]