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SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
7540 Group
MITSUBISHI MICROCOMPUTERS
6
PRELIMINARY
Notice: This is not a final specification.
Some parametric limits are subject to change.
PIN DESCRIPTION
Table 1 Pin description
Pin
Vcc, Vss
V
REF
Function
Apply voltage of 2.2–5.5 V to Vcc, and 0 V to Vss.
Reference voltage input pin for A-D converter
Chip operating mode control pin, which is always connected to Vss.
Reset input pin for active “L”
Input and output pins for main clock generating circuit
Connect a ceramic resonator or quartz crystal oscillator between the X
IN
and X
OUT
pins.
For using RC oscillator, short between the X
IN
and X
OUT
pins, and connect the capacitor and resistor.
If an external clock is used, connect the clock source to the X
IN
pin and leave the X
OUT
pin open.
Function expect a port function
Name
Power source
Analog reference
voltage
CNVss
Reset input
Clock input
Clock output
I/O port P0
I/O port P1
I/O port P2
I/O port P3
CNVss
RESET
X
IN
P0
0
/CNTR
1
P0
1
/TY
OUT
P0
2
/TZ
OUT
P0
3
/TX
OUT
P0
4
–P0
7
P1
0
/RxD
1
P1
1
/TxD
1
8-bit I/O port.
I/O direction register allows each pin to be individually pro-
grammed as either input or output.
CMOS compatible input level
CMOS 3-state output structure
Whether a built-in pull-up resistor is to be used or not can be
determined by program.
5-bit I/O port
I/O direction register allows each pin to be individually pro-
grammed as either input or output.
CMOS compatible input level
CMOS 3-state output structure
CMOS/TTL level can be switched for P1
0,
P1
2
and P1
3
8-bit I/O port having almost the same function as P0
CMOS compatible input level
CMOS 3-state output structure
8-bit I/O port
I/O direction register allows each pin to be individually programmed as either input or output.
CMOS compatible input level (CMOS/TTL level can be switched for P3
6
and P3
7
).
CMOS 3-state output structure
P3
0
to P3
6
can output a large current for driving LED.
Whether a built-in pull-up resistor is to be used or not can be
determined by program.
Key-input (key-on wake up
interrupt input) pins
Timer Y, timer Z, timer X and
timer A function pin
Serial I/O1 function pin
Serial I/O1 function pin
Serial I/O2 function pin
X
OUT
Timer X function pin
Input pins for A-D converter
Interrupt input pins
P1
2
/S
CLK1
/S
CLK2
P1
3
/S
RDY1
/S
DATA2
P1
4
/CNTR
0
P2
0
/AN
0
–
P2
7
/AN
7
P3
0
–P3
5
P3
6
/INT
1
P3
7
/INT
0