8
8-23
INPUT/OUTPUT PORTS AND PIN FUNCTIONS
32180 Group User’s Manual (Rev.1.0)
8.3 Input/Output Port Related Registers
(3) PIEN0 (Port input enable) bit (Bit 15)
This bit is used to prevent current from flowing into the port input pins.
Because the input/output ports are disabled against input after 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
a low-level input applied. Consequently, if a peripheral input function is selected for any port (uncontrolled
pin) while disabled against input by using the Port Operation Mode Register, the port may operate unexpect-
edly due to the low-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 (high or low)
(2) Select a function using the port operation mode bit
During boot mode, the pins shared with serial I/O functions are enabled for input and can therefore be
protected against current flowing in from the pins other than serial I/O 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 PIEN0 Bit
Mode Name Controllable Pins Uncontrolled Pins
P00–P07, P10–P17, P20–P27 P221, P223,
P30–P37, P41–P47, P61–P63 FP, MOD0, MOD1, SBI#, RESET#
Single-chip P65–P67, P70–P77, P82–P87
P93–P97, P100–P107, P110–P117
P124–P127, P130–P137, P140–P147
P150–P157, P160–P167, P172–P177
P180–P187, P190–P197, P200–P203
P210–P217, P220–P222, P224–P227
P61–P63, P65–P67, P70–P77 P00–P07, P10–P17
P82–P87, P93–P97, P100–P107 P20–P27, P30–P37
External extension P110–P117, P124–P127, P130–P137 P41–P47, P221, P223–P227
Microprocessor P140–P147, P150–P157, P160–P167 FP, MOD0, MOD1, SBI#, RESET#
P172–P177, P180–P187, P190–P197
P200–P203, P210–P217, P220
P222
P00–P07, P10–P17, P20–P27 P65, P66, P82–P87, P101
P30–P37, P41–P47, P61–P63 P135–P136, P174–P177, P200–P203
Boot P67, P70–P77, P93–P97 P221, P223,
(single-chip) P100, P102–P107, P110–P117, P124–P127 FP, MOD0, MOD1, SBI#, RESET#
P130–P134, P137, P140–P147, P150–P157
P160–P167, P172–P173, P180–P187
P190–P197, P210–P217, P220
P222, P224–P227
To Next Page
Loading...
Need help?
General
