NEC PD75402A User Manual
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CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
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SBI definition
The SBI serial data format and the meaning of the signals used are explained in the following section. Serial data
transmitted via the SBI is classified into three types: Commands, addresses and data. Serial data forms a frame with
the configuration shown below.
Address, command and data transfer timing is shown in Fig. 5-33.
Fig. 5-33 SBI Transfer Timing
The bus release signal and command signal are output by the master. The BUSY signal is output by the slave.
ACK can be output by either the master or slave (normally output by the 8-bit data receiver).
The serial clock is output by the master continuously from the start of an 8-bit data transfer until BUSY is released.
Address Transfer
SCK
SB0
SCK
Bus Release
Signal
Command Transfer
Command Signal
Data Transfer
SCK
SB0
SB0
8
9
A7
A0
C7
C0
D7
D0
9
9
8
BUSY
ACK
BUSY
READY
ACK
BUSY
READY
ACK