INPUT/OUTPUT PORTS AND PIN FUNCTIONS
8.2 Selecting Pin Functions
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8.2 Selecting Pin Functions
Each input/output port serves dual functions sharing the pin with other internal peripheral I/O or extended external
bus signal line (or triple functions sharing the pin with two or more peripheral I/O functions). Pin functions are
selected depending on the current operation mode or by setting the input/output port operation mode registers.
P0–P4 and P224–P227, when the CPU is set to operate in processor mode, all are switched to serve as signal
pins for external access. The CPU operation mode is determined depending on how the MOD0 and MOD1 pins
are set (see the table below).
Table 8.2.1 CPU Operation Modes and P0–P4 and P224–P227 Pin Functions
MOD0
VSS
MOD1
VSS
Operation Mode
P0–P4 and P224–P227 Pin Function
Input/output port pin
Single-chip mode
VSS
VCCE
VSS
External extension mode
Input/output port pin or extended external signal pin (Note 1)
VCCE
VCCE
Processor mode (FP pin = VSS) Extended external signal pin
Reserved (use inhibited)
VCCE
–
Note 1: P41–P43 serve as dedicated external bus interface signal pins.
Note: • VCCE and VSS are connected to 5 or 3.3 V and GND, respectively.
Each input/output port has their functions switched between input/output port pins and internal peripheral I/O pins
by setting the respective port operation mode registers. If any internal peripheral I/O has two or more pin functions,
use the register provided for that peripheral I/O to select the desired pin function.
Note that FP and MOD1 pin settings during internal flash memory programming do not affect the pin functions.
32180 Group User’s Manual (Rev.1.0)
8-3
RENESAS [ RENESAS TECHNOLOGY CORP ]
