M32C/8B Group
1. Overview
REJ03B0242-0100 Rev.1.00 Nov 01, 2009
Page 15 of 67
1.5
Pin Functions
Table 1.11
Pin Functions (100-Pin and 144-Pin Packages) (1/3)
Item
Pin Name
I/O
Type
Supply
Voltage
Description
Power supply
VCC1,VCC2
VSS
Apply 3.0 to 5.5 V to pins VCC1 and VCC2, and 0 V to the VSS pin.
Meet the input condition of VCC1
≥ VCC2.
Analog power
supply input
AVCC
AVSS
VCC1
Power supply input pins to the A/D converter and D/A converter.
Connect the AVCC pin to VCC1, and the AVSS pin to VSS.
Reset input
RESET
I
VCC1
The MCU is placed in the reset state while applying an “L” signal to
the RESET pin.
CNVSS
I
VCC1
This pin switches processor mode. Apply an “L” to the CNVSS pin
to start up in single-chip mode, or an “H” to start up in
microprocessor mode and boot mode.
External data
bus width
select input
BYTE
I
VCC1
This pin switches data bus width in external memory space 3. A
data bus is 16 bits wide when the BYTE pin is held “L” and 8 bits
wide when it is held “H”. Fix to either “L” or “H”. Apply an “L” to the
BYTE pin in single-chip mode.
Bus control
Pins
D0 to D7
I/O
VCC2
Data (D0 to D7) input/output pins while accessing an external
memory space with separate bus.
D8 to D15
I/O
VCC2
Data (D8 to D15) input/output pins while accessing an external
memory space with 16-bit separate bus.
A0 to A22
O
VCC2
Address bits (A0 to A22) output pins.
A23
O
VCC2
Inverted address bit (A23) output pin.
A0/D0 to
A7/D7
I/O
VCC2
Data (D0 to D7) input/output and 8 low-order address bits (A0 to
A7) output are performed by time-sharing these pins while
accessing an external memory space with multiplexed bus.
A8/D8 to
A15/D15
I/O
VCC2
Data (D8 to D15) input/output and 8 middle-order address bits (A8
to A15) output are performed by time-sharing these pins while
accessing an external memory space with 16-bit multiplexed bus.
CS0 to CS3
O
VCC2
Chip-select signal output pins used to specify external devices.
WRL/WR
WRH/BHE
RD
O
VCC2
WRL, WRH, (WR, BHE) and RD signal output pins. WRL and WRH
can be switched with WR and BHE by a program.
WRL, WRH and RD are selected:
If external data bus is 16 bits wide, data is written to an even
address in external memory space while an “L” is output from the
WRL pin. Data is written to an odd address while an “L” is output
from the WRH pin.
Data is read while an “L” is output from the RD pin.
WR, BHE and RD are selected:
Data is written while an “L” is output from the WR pin.
Data is read while an “L” is output from the RD pin.
Data in odd address is accessed while an “L” is output from the
BHE pin. Select WR, BHE and RD when an external data bus is
8 bits wide.
ALE
O
VCC2
ALE signal is used for the external devices to latch address signals
when the multiplexed bus is selected.
HOLD
I
VCC2
The MCU is placed in the hold state while an “L” signal is applied to
the HOLD pin.
HLDA
O
VCC2
The HLDA pin outputs an “L” while the MCU is placed in the hold state.
RDY
I
VCC2
Bus is placed in the wait state while an “L” signal is applied to the
RDY pin.