Pin Name

I/O

Mask

Option

Description

PE0~PE1

I/O

Pull-high

or None

Bidirectional input/output port. Software* instruction determine the CMOS output or

Schmitt Trigger input with or without pull-high resistor.

If PE0 output 1, rising edge of PC2 trigger INT circuit.

PE0 output 0, falling edge of PC2 trigger INT circuit.

PE2

O

This pin is a CMOS output structure. The pad can function as LED (SCR) drivers for

PE3

O

This pin is a CMOS output structure. The pad can function as LED (NUM) drivers

PE4

O

This pin is a CMOS output structure. The pad can function as LED (CAP) drivers for

VDD

¾¾

Positive power supply

VSS

¾¾

Negative power supply, ground

RESET

I

¾

Chip reset input. Active low. Built-in power-on reset circuit to reset the entire chip.

Chip can also be externally reset via RESET pin

OSC1

OSC2

I

O

Crystal or RC

OSC1, OSC2 are connected to an RC network or a crystal for the internal system

clock. In the case of RC operation, OSC2 is the output terminal for the 1/4 system

clock; A 110k

W resistor is connected to OSC1 to generate a 2 MHZ frequency.

Note:

*: Software means the HT

-IDE (Holtek Integrated Development Environment) can be configured by mask op-

tion.

Absolute Maximum Ratings

Supply Voltage ........................................

-0.3V to 5.5V

Storage Temperature ...........................

-50°Cto125°C

Operating Temperature ..........................

-25°Cto70°C

Note: These are stress ratings only. Stresses exceeding the range specified under

²Absolute Maximum Ratings² may

cause substantial damage to the device. Functional operation of this device at other conditions beyond those

listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliabil-

ity.

D.C. Characteristics

Ta=25

°C

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Conditions

Operating Voltage

¾¾

2.4

¾

5.5

V

Operating Current (Crystal OSC)

3V

¾

0.7

1.5

mA

5V

¾

25

mA

Operating Current (RC OSC)

3V

¾

0.5

1

mA

5V

¾

25

mA

Standby Current (WDT enabled)

3V

No load, system HALT

¾¾

8

mA

5V

¾¾

15

mA

Standby Current (WDT Disabled)

3V

No load, system HALT

¾¾

3

mA

5V

¾¾

6

mA

Input Low Voltage for I/O Ports (Schmitt)

3V

¾

0

¾

0.9

V

5V

¾

0

¾

1.5

V

Input High Voltage for I/O Ports (Schmitt)

3V

¾

2.1

¾

3V

5V

¾

3.5

¾

5V

HT82K68A

Rev. 1.10

3

November 20, 2001