4524 Datasheet, PDF (54/161 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4524 Group
(5) How to use serial I/O
Figure 40 shows the serial I/O connection example. Serial I/O inter-
rupt is not used in this example. In the actual wiring, pull up the
wiring between each pin with a resistor. Figure 40 shows the data
transfer timing and Table 16 shows the data transfer sequence.
Master (clock control)
Slave (external clock)
D3
SCK
SOUT
SI N
(Bit 3)
00
(Bit 0)
11
Serial I/O control
register J1
Serial I/O port
SCK,SOUT,SIN
Instruction clock/8 selected
as synchronous clock
SRDY signal
D3
SCK
SIN
SOUT
(Bit 3)
11
(Bit 0)
11
Serial I/O control
register J1
Serial I/O port
SCK,SOUT,SIN
External clock selected
as synchronous clock
(Bit 3)
0✕
(Bit 0)
✕✕
Interrupt control
register V2
Serial I/O interrupt
enable bit
(SNZSI instruction valid)
(Bit 3)
0✕
(Bit 0)
✕✕
Interrupt control
register V2
Serial I/O interrupt
enable bit
(SNZSI instruction valid)
Fig. 40 Serial I/O connection example
✕: Set an arbitrary value.
Rev.2.00 Jul 27, 2004 page 54 of 159
REJ03B0091-0200Z