M16C80 Datasheet, PDF (217/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
26. Programmable I/O Ports
Port control register (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
Symbpl
PCR
Address
03FF16
When reset
XXXXXXX02
Bit symbol
Bit name
PCR0
Port P1 control register
Function
0 : Function as common CMOS
port
1 : Function as N-ch open drain
port
(Note 2)
RW
Nothing is assigned.
When write, set "0". When read, their contents are indeterminate.
Note 1: Since P1 operates as the data bus in memory expansion mode and
microprocessor mode, do not set the port control register. However, it is
possible to select the CMOS port or N-channel open drain to the usable port
as I/O port by setting.
Note 2: This function is designed to permanently turn OFF the Pch of the CMOS port.
It does not make port 1 a full open drain. Therefore, the absolute maximum
input voltage rating is [-3 to Vcc + 0.3V].
Figure 26.15 Port control register
Rev.1.00 Aug. 02, 2005 ^{Page 206} of 329
REJ09B0187-0100