Mitsubishi Electric M32R Series User Manual page 198

INPUT/OUTPUT PORTS AND PIN FUNCTIONS
8
8.1 Outline of Input/Output Ports
8.1 Outline of Input/Output Ports
The 32170 has a total of 157 input/output ports from P0 to P22 (of which P5 is reserved for future
use, however). These input/output ports can be set for input or output mode by a direction register.
Each input/output port serves as a dual-function or triple-function pin, sharing the pin with other
internal peripheral I/O or extended external bus signal line. Pin functions are selected depending on
the device's operation mode you choose or by setting the input/output port's Operation Mode
Register. (If any internal peripheral I/O has still another function, you need to set the register
provided for that peripheral I/O.)
As a new function, the 32170 internally contains a Port Input Function Enable bit that can be used
to prevent current from flowing into the input ports. This helps to simplify the software and hardware
processing to be performed immediately after reset or during flash rewrite. To use any ports in input
mode, you need to set the Port Input Function Enable bit accordingly.
The input/output ports are outlined in the next pages.
8-2 Ver.0.10