M16C29 Datasheet, PDF (353/499 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/Tiny SERIES

M16C/29 Group
19. Programmable I/O Ports
Table 19.1 Unassigned Pin Handling in Single-chip Mode
Pin Name
Setting
Ports P0 to P3, P6 to P10
Enter input mode and connect each pin to VSS via a resistor (pull-down);
or enter output mode and leave the pins open ^(1,2,4)
XOUT
Leave pin open ⁽³⁾
XIN
Connect pin to VCC via a resistor (pull-up) ⁽⁵⁾
AVCC
Connect pin to VCC
AVSS, VREF
Connect pin to VSS
NOTES:
1. If the port enters output mode and is left open, it is in input mode before output mode is entered by program
after reset. While the port is in input mode, voltage level on the pins is indeterminate and power consumption
may increase. Direction register setting may be changed by noise or failure caused by noise. Configure
direction register settings regulary to increase the reliability of the program.
2. Use the shortest possible wiring to connect the MCU pins to unassigned pins (within 2 cm).
3. When the external clock is applied to the XIN pin, set the pin as written above.
4. In the 64-pin package, set bits PACR2, PACR1, and PACR0 in the PACR register to 0102. In the 80-pin
package, set bits PACR2, PACR1, and PACR0 to 0112.
5. When the main clock oscillation is not used, set the CM05 bit in the CM0 register to 1 (main clock stops) to
reduce power consumption.
MCU
Port P0 to P3, P6 to P10
(1) _{(Input mode)}
···
(Input mode)
(Output mode)
XIN
XOUT
AVCC
···
Open
Open
VCC
AVSS
Vref
VSS
In single-chip mode
NOTE:
1. When using the 64-pin package, set bits PACR2, PACR1, and PACR0 to 0102.
When using the 80-pin package, set bits PACR2, PACR1, and PACR0 to 0112.
Figure 19.13 Unassigned Pin Handling
Rev. 1.12 Mar.30, 2007 ^{page 329} of 458
REJ09B0101-0112