Block Diagram Of 8-Bit Serial I/O - Fujitsu Semiconductor Controller MB89950/950A Hardware Manual

9.2

Block Diagram of 8-bit Serial I/O

Each channel of the 8-bit serial I/O consists of the following four blocks:
• Shift clock controller
• Shift clock counter
• Serial data register (SDR)
• Serial mode register (SMR)
I Block diagram of 8-bit serial I/O
D0 to D7
MSB first
P43/SI
Pin
P44/SO
Pin
P45/SCK
Pin
t : Instruction cycle
inst
Note: The SO and SCK output serve as UART outputs. They can be used as the outputs of the serial I/O when the
RESL bit of SMC2 in the UART is "1".
Figure 9.2-1 Block diagram of 8-bit serial I/O
Transfer direction
selection
(Shift direction)
Serial data register (SDR)
Output enable
2t
inst
8t
inst
32t
inst
Shift clock controller
Output buffer
Internal data bus
D7 to D0
LSB first
Output buffer
Output enable
2
Shift clock selection
/
Clear
Shift clock counter
CHAPTER 9 8-BIT SERIAL I/O
D7 to D0
SST
BDS
CKS0
CKS1
SOE
SCKE
SIOE
SIOF
Serial mode register
(SMR)
IRQ5
171