M38203M4 Datasheet, PDF (190/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.5 Serial I/O1
sShift clock
Ordinarily, when clock synchronous transfer is performed between microcomputers, an internal clock
is selected for one of them, and it outputs 8 shift clocks generated by a start of transmit operation from
the P46/SCLK1 pin. An external clock is selected for the other microcomputer, and it uses the clock
input from the P46/SCLK1 pin as a shift clock. Figure 2.5.2 shows a shift clock.
3820 group Œ
3820 group 
XIN
8
Receive buffer register
RxD
Receive shift register
1/4
Clock control circuit
BRG
1/(n+1) 1/4
SCLK1
Shift clock
TxD
SCLK1
8
Transmit buffer register
Transmit shift register
Clock control circuit
Transmit shift register
TxD
Transmit buffer register
8
Internal clock is selected
RxD _{Receive shift register}
Receive buffer register
8
External clock is selected
Fig. 2.5.2 Shift clock
2–104
3820 GROUP USER’S MANUAL