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 the keyboard. I
OL
=18mA at V
OL
=3.4V
PE3
O
This pin is a CMOS output structure. The pad can function as LED (NUM) drivers
for the keyboard. I
OL
=18mA at V
OL
=3.4V
PE4
O
ThispinisaCMOSoutputstructure.ThepadcanfunctionasLED(CAP)driversfor
the keyboard. I
OL
=18mA at V
OL
=3.4V
VDD
Positive power supply
VSS
Negative power supply, ground
RESET
I
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
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
option.
Absolute Maximum Ratings
Supply Voltage ..........................V
SS
0.3V to V
SS
+6.0V
Storage Temperature ........................... 50 C to 125 C
Input Voltage .............................V
SS
0
.
3V to V
DD
+0.3V
Operating Temperature .......................... 25 C to 70 C
Note: These are stress ratings only. Stresses exceeding the range specified under Absolute Maximum Ratings 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
reliability.
D.C. Characteristics
Ta=25 C
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
DD
Conditions
V
DD
Operating Voltage
1.8
5.5
V
I
DD1
Operating Current (Crystal OSC)
3V
No load, f
SYS
= 6MHz
0.7
1.5
mA
5V
2
5
mA
I
DD2
Operating Current (RC OSC)
3V
No load, f
SYS
= 6MHz
0.5
1.5
mA
5V
2
5
mA
I
STB1
Standby Current (WDT enabled)
3V
Noload,systemHALT
8
A
5V
15
A
I
STB2
Standby Current (WDT Disabled)
3V
Noload,systemHALT
3
A
5V
6
A
V
IL1
Input Low Voltage for I/O Ports
(Schmitt)
3V
0
0.3V
DD
V
5V
0
0.3V
DD
V
V
IH1
Input High Voltage for I/O Ports
(Schmitt)
3V
0.7V
DD
V
DD
V
5V
0.7V
DD
V
DD
V
HT82K68E-L/HT82K68A-L
Rev. 1.00
4
August 9, 2007