NEC PD75P402, PD75402A user manual Slave Selection by Address

CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

(c)Address

An address is 8-bit data output by the master to slaves connected to the bus line in order to select a particular slave.

SCK

SB0

Bus Release Signal

	Fig. 5-36		Address
1	2	3	4		5		6		7	8
A7	A6	A5		A4		A3		A2	A1	A0
					Address

Command Signal

The 8-bit data following the bus release signal and command signal is defined as an address. In a slave this condition is detected by hardware and a check is performed by hardware to see if the 8-bit data matches the slave’s own specification number (slave address). If the 8-bit data matches the slave address, that slave is determined to have been selected and communication is subsequently performed with the master until a disconnect directive is received from the master.

Fig. 5-37 Slave Selection by Address

Master

Sends Address of Slave

Slave 1

Slave 2

Not Selected

Selected

Slave 3

Not Selected

Slave 4

Selected

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