CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

(a) Bus release signal (REL)

The bus release signal indicates that the SB0 line has changed from low to high when the SCK line is high (when the serial clock is not being output). This signal is output by the master.

Fig. 5-34 Bus Release Signal

SCK “H”

SB0

The bus release signal indicates that the master is about to send an address to a slave. Slaves incorporate hardware to detect the bus release signal.

(b) Command signal (CMD)

The command signal indicates that the SB0 line has changed from high to low when the SCK line is high (when the serial clock is not being output). This signal is output by the master.

Fig. 5-35 Command Signal

SCK “H”

SB0

Slave incorporate hardware to detect the command signal.

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NEC PD75402A, PD75P402 user manual Bus release signal REL, Command signal CMD, Sck H, SCK H SB0