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CHAPTER 14 8-BIT SERIAL I/O
Block Diagram for 8-bit Serial I/O Pins
Figure 14.3-1 Block Diagram for 8-bit Serial I/O Pins
Note:
When "pull-up resistor available" is selected in the pull-up setting register, the pin state in stop mode
(SPL = 1) becomes high (pull-up state), not Hi-Z. During the reset, however, pull-up becomes invalid
and the pin state becomes Hi-Z.
DDR
Pch
Nch
SCK
PDR
PUL
P30/UCK/SCK
P32/UI/SI
SI
P30/UCK/SCK
P31/UO/SO
P32/UI/SI
(SPL=1)
Internal data bus
PDR readResource outputStop mode (SPL = 1)
Resource
output
enable
Resource
output
available
Pull-up resistor
PDR read
(At read-modify-write)
Output latch
PDR write Pin
PUL read
PUL write
DDR write Stop mode