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A
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R
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Page 9
1. Overview
p
u
o
r
G
0
8
/
C
6
1
M
VCC, VSS
CNVSS
XIN
XOUT
BYTE
AVCC
AVSS
VREF
P00 to P07
D0 to D7
P10 to P17
D8 to D15
P20 to P27
A0 to A7
A0/D0 to
A7/D7
P30 to P37
A8 to A15
A8/D8 to
A15/D15
Signal name
Power supply
input
CNVSS
Reset input
Clock input
Clock output
External data
bus width
select input
Analog power
supply input
Reference
voltage input
I/O port P0
I/O port P1
I/O port P2
I/O port P3
Supply 4.2 (2.7) to 5.5 V to the VCC pin. Supply 0 V to the VSS pin.
Function
This pin switches between processor modes. Connect it to the VSS
when operating in single-chip or memory expansion mode after reset.
Connect it to the VCC when in microprocessor mode after reset.
An “L” on this input resets the microcomputer.
These pins are provided for the main clock generating circuit. Connect
a ceramic resonator or crystal between the XIN and the XOUT pins. To
use an externally derived clock, input it to the XIN pin and leave the
XOUT pin open.
This pin selects the width of an data bus in the external area 3. A 16-
-bit width is selected when this input is “L”; an 8-bit width is selected
when this input is “H”. This input must be fixed to either “H” or “L”.
When not using the external bus, connect this pin to VSS.
This pin is a power supply input for the A/D converter. Connect this
pin to VCC.
This pin is a power supply input for the A/D converter. Connect this
pin to VSS.
This pin is a reference voltage input for the A/D converter.
This is an 8-bit CMOS I/O port. It has an input/output port direction
register that allows the user to set each pin for input or output
individually. When set for input in single chip mode, the user can
specify in units of four bits via software whether or not they are tied to
a pull-up resistance. In memory expansion and microprocessor
mode, an built-in pull-up resistance cannot be used. However, it is
possible to select pull-up resistance presence to the usable port as I/
O port by setting.
When set as a separate bus, these pins input and output data (D0–D7).
This is an 8-bit I/O port equivalent to P0. P15 to P17 also function as
external interrupt pins as selected by software.
When set as a separate bus, these pins input and output data (D8–D15).
This is an 8-bit I/O port equivalent to P0.
These pins output 8 low-order address bits (A0–A7).
If a multiplexed bus is set, these pins input and output data (D0–D7)
and output 8 low-order address bits (A0–A7) separated in time by
multiplexing.
This is an 8-bit I/O port equivalent to P0.
These pins output 8 middle-order address bits (A8–A15).
If the external bus is set as a 16-bit wide multiplexed bus, these pins
input and output data (D8–D15) and output 8 middle-order address
bits (A8–A15) separated in time by multiplexing.
Pin name
I
O
I
I/O
I/O type
Analog power
supply input
I/O
O
I/O
O
I/O
RESET
MA0 to MA7
If accessing to DRAM area, these pins output row address and
column address separated in time by multiplexing.
O
1.6 Pin Description (1)