Chapter 1 Hardware Structure
Pad Name
I/O
Options
Description
The 1/4 LCD duty cycle configuration option will de-
termine whether pin COM3/SEG47 is configured as a
SEG47 segment driver or as a common COM3 output
driver for the LCD panel. COM0~COM2 are the LCD
common outputs.
LCD driver outputs for LCD panel segments
OSC1 and OSC2 are connected to an external RC
network or external crystal (determined by configura-
tion option) for the internal system clock. For external
RC system clock operation, OSC2 is an output pin for
1/4 system clock. If an RTC oscillator on pins OSC3
and OSC4 is used as a system clock, then the OSC1
and OSC2 pins should be left floating.
OSC3 and OSC4 are connected to a 32768Hz crystal
to form a Real Time Clock for timing purposes or to
form a system clock.
Schmitt Trigger reset input, active low.
Positive power supply
Negative power supply, ground
COM0~COM2
COM3/SEG47
O
1/2, 1/3 or 1/4
Duty
SEG0~SEG39
O
¾
OSC1
OSC2
I
O
Crystal or RC
OSC3
OSC4
RES
VDD
VSS
I
O
I
¾
¾
RTC or
System Clock
¾
¾
¾
Note
1. Each pin on PA can be programmed through a configuration option to have a wake-up function.
2. Only pins PA0~PA3, PC0~PC3 and PC4~PC7 have a pull-high resistor configuration option.
These pull-high options can only be selected if these four pins are configured as NMOS types.
If the pull-high option is selected then it will apply to all four pins, individual pins cannot be
selected to have pull-high resistors. If setup as CMOS outputs the pull-high configuration
option is disabled.
Absolute Maximum Ratings
Supply Voltage (Except HT49C30L, HT49C50L, HT49C70L) ....................V
SS
-0.3V
to V
SS
+6.0V
Supply Voltage (For HT49C30L, HT49C50L, HT49C70L) ..........................V
SS
-0.3V
to V
SS
+2.5V
Input Voltage ..............................................................................................V
SS
-0.3V
to V
DD
+0.3V
Storage Temperature ............................................................................................-50°C to 125°C
Operating Temperature ...........................................................................................-40°C to 85°C
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 ex-
treme conditions may affect device reliability.
15
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