NEC PD75P402 Manual do Utilizador descarregar pdf (Página 108)

CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

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

slave.

Fig. 5-36 Address

SCK

SB0

Bus Release Signal

Command Signal

Address

1 2 3 4 5 6 7 8

A7 A6 A5 A4 A3 A2 A1 A0

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

Slave 1

Slave 2

Slave 3

Slave 4

Not Selected

Selected

Not Selected

Selected

Sends Address

of Slave

1 2 ... 103 104 105 106 107 108 109 110 111 112 113 ... 194 195

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NEC PD75P402 Manual do Utilizador Página 108