
M16C/30P Group
1. Overview
Rev.1.22
REJ03B0088-0122
Mar 30, 2007
Page 12 of 53
1.6
Pin Description
I : Input O : Output I/O : Input and output
Table 1.8
Signal Name
Power supply input
Pin Description (1)
Pin Name
VCC1, VCC2
VSS
AVCC
AVSS
RESET
I/O Type
I
Description
Apply 2.7 to 5.5 V to the VCC1 and VCC2 pins and 0 V to the V
SS
pin. The VCC apply condition is that VCC1 = VCC2.
Applies the power supply for the A/D converter. Connect the AVCC
pin to VCC1. Connect the AVSS pin to VSS.
The microcomputer is in a reset state when applying “L” to the this
pin.
Switches processor mode. Connect this pin to VSS to when after
a reset to start up in single-chip mode. Connect this pin to VCC1 to
start up in microprocessor mode.
Switches the data bus in external memory space. The data bus is
16 bits long when the this pin is held "L" and 8 bits long when the
this pin is held "H". Set it to either one. Connect this pin to VSS
when an single-chip mode.
Inputs and outputs data (D0 to D7) when these pins are set as the
separate bus.
Inputs and outputs data (D8 to D15) when external 16-bit data bus
is set as the separate bus.
Output address bits (A0 to A19).
Output CS0 to CS3 signals. CS0 to CS3 are chip-select signals to
specify an external space.
Output WRL, WRH, (WR, BHE), RD signals. WRL and WRH or
BHE and WR can be switched by program.
WRL, WRH and RD are selected
The WRL signal becomes "L" by writing data to an even address in
an external memory space.
The WRH signal becomes "L" by writing data to an odd address in
an external memory space.
The RD pin signal becomes "L" by reading data in an external
memory space.
WR, BHE and RD are selected
The WR signal becomes "L" by writing data in an external memory space.
The RD signal becomes "L" by reading data in an external memory space.
The BHE signal becomes "L" by accessing an odd address.
Select WR, BHE and RD for an external 8-bit data bus.
ALE is a signal to latch the address.
While the HOLD pin is held "L", the microcomputer is placed in a
hold state.
In a hold state, HLDA outputs a "L" signal.
While applying a "L" signal to the RDY pin, the microcomputer is
placed in a wait state.
Analog power
supply input
Reset input
I
I
CNVSS
CNVSS
I
External data bus
width select input
BYTE
I
Bus control pins
D0 to D7
I/O
D8 to D15
I/O
A0 to A19
CS0 to CS3
O
O
WRL/WR
WRH/BHE
RD
O
ALE
HOLD
O
I
HLDA
RDY
O
I