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INPUT/OUTPUT PORTS AND PIN FUNCTIONS
8
8-31
32185/32186 Group Hardware Manual
Rev.1.10 REJ09B0235-0110 May 15, 07
8.3 Input/Output Port Related Registers
(3) PIEN0 (Port input enable) bit (Bit 15)
This bit is used to prevent shoot-through current from flowing into the port input pins.
Because the input/output ports are disabled against input upon exiting reset, if any ports need to be used in
input mode they must be enabled for input by setting this bit to "1."
When disabled against input, the input/output ports are in a state equivalent to a situation where the pin has
"L" level input applied. Consequently, if a peripheral input function (uncontrolled pin) is selected for any port
while disabled against input by using the Port Operation Mode Register, the port may operate unexpectedly
due to the "L" level input on it.
The following shows the procedure for selecting a peripheral input function.
(1) Enable the port for input when its pin level is valid ("H" or "L")
(2) Select a function using the port operation mode bit
During boot mode, the pins shared with serial interface functions are enabled for input and can therefore be
protected against shoot-through current flowing in from the pins other than serial interface functions during
flash programming by clearing PIEN0.
The table below lists the pins that can be controlled by the PIEN0 bit in each operation mode.
Table 8.3.2 Pins Controllable by Port Input Enable Bit
Mode Name
Controllable Pins
Uncontrolled Pins
P00–P07, P10–P17, P20–P27
P221, FP, SBI#, MOD0, MOD1, MOD2, RESET#
P30–P37, P41–P47, P61–P63
Single-chip
P70–P77, P82–P87, P93–P97
P100–P107, P110–P117, P124–P127
P130–P137, P150, P153, P174, P175
P220, P224, P225
P61–P63, P70–P77, P82–P87
P00–P07, P10–P17
External extension
P93–P97, P100–P107, P110–P117
P20–P27, P30–P37
Microprocessor
P126, P127, P130–P137
P41–P47, P124, P125, P221, P224, P225
P150, P153, P174, P175, P220
FP, SBI#, MOD0, MOD1, MOD2, RESET#
P00–P07, P10–P17, P20–P27
P82–P87, P174, P175, P221
Boot
P30–P37, P41–P47, P61–P63
FP, SBI#, MOD0, MOD1, MOD2, RESET#
(single-chip)
P70–P77, P93–P97, P100–P107
P110–P117, P124–P127, P130–P137
P150, P153, P220, P224, P225