8-Bit Serial I/O; Fig. 2.38 8-Bit Serial I/O Block Diagram - Fujitsu MB89140 Series Hardware Manual

8-BIT SERIAL I/O

D0 to D7
(MSB first)
SI input
P34/SI
synchronous
circuit
P33/SO
Output enable
Output enable
P32/SCK
Internal
clock pulse
HARDWARE CONFIGURATION

2.11 8-BIT SERIAL I/O

8-bit serial data transfer is possible by the clock synchronous method.
LSB first or MSB first can be selected for data transfer.
Four shift-clock modes (three internal and one external) can be selected.
Block Diagram
Internal data bus
(Shift direction)
Serial data register (SDR)
synchronous
Control
circuit
3
Shift-clock counter

Fig. 2.38 8-bit Serial I/O Block Diagram

Register list
The 8-bit serial I/O consists of serial mode register (SMR) and serial data
register (SDR).
Address: 001C
H
Address: 001D
H
2-70
D7 to D0
(LSB first)
Transfer
direction
select
SO output
circuit
2
Shift-clock
pulse select
Clear
8 bit
SMR R/W Serial mode register
SDR R/W Serial data register
D7 to D0
SIOF
SIOE
SCKE
SOE
CKS1
CKS0
BDS
Overflow
SST
Serial mode
register (SMR)
IRQ8