Serial Communication With Multiple Devices; Example System Configuration Using The Serial Bus Interface - NEC PD78212 User Manual

8-bit single-chip microcomputer sub-series

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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

Chapter 16 Application Examples