GMS84512 Datasheet, PDF (53/123 Pages) Hynix Semiconductor – 8-BIT SINGLE CHIP MICROCOMPUTER

GMS 84512 / 84524
3.5 Serial I/O
The serial I/O is 8-bit clock sychronous type and is consisted of serial I/O register, serial I/O mode
register, clock selection circuit octal counter and control circuit. The Sout pin is degined to Input
and Output. So serial I/O interface can be operated with minimum two pin.
Data BUS
7
SIOM
-
6
6
0
IOSW SM1 SM0 SCK1 SCK0 SIOST SOSF
SM1
SM0
Exclk
Sout
Sin
2
PS3
PS4
MUX
PS5
Control
Circuit
Octal Counter
Sclk
1
MUX
0
SIOR
76543210
8
Data BUS
FIG. 3.5.1 Block Diagram of Serial I/O
IFSIO
3.5.1 Serial I/O Data Register
Serial I/O Data Register SIORis a 8-bit Shift Register. First LSB is send or is received.
SIOR
<00D9_H>
R/W
7
R/W
6
R/W
5
R/W
4
R/W
3
R/W
2
R/W
1
R/W
0
D7 D6 D5 D4 D3 D2 D1 D0
Initial value when MCU Reset
[ Not initialized ]
At transmittion
Sending Data at Sending
Receiving Data at Receiving
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