CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

(7)3-wire serial I/O mode applications

(a)To transfer data MSB-first (master operation) using a 262 kHz transfer clock (when operating at 4.19 MHz).

<Sample program>

 

MOV

XA, #10000010B

 

MOV

CSIM, XA

; Transfer mode setting

MOV

XA, TDATA

; TDATA is transfer data storage address

MOV

SIO, XA

; Transfer data setting & start of transfer

Note From the second time onward, the transfer can be started by setting data in SIO (MOV SIO, XA or XCH XA, SIO).

μPD75402A

SCK

SCK

SO/SB0

SI

In this application the μPD75402A SI pin can be used as an input port.

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NEC PD75P402, PD75402A user manual Wire serial I/O mode applications, MOV XA, Tdata, Mov Sio, Xa, SCK SO/SB0