HT49R50 Holtek Semiconductor Inc, HT49R50 Datasheet - Page 6

• Manufacturer Part Number: HT49R50
• Description: 8-Bit Microcontroller
• Manufacturer: Holtek Semiconductor Inc

Pin Description
PA0/BZ
PA1/BZ
PA2
PA3/PFD
PA4~PA7
PB0/INT0
PB1/INT1
PB2/TMR0
PB3/TMR1
PB4~PB7
PC0~PC3
VSS
VLCD
V1,V2,C1,C2
SEG32/COM3
COM2~COM0
SEG31~SEG0
OSC4
OSC3
VDD
OSC2
OSC1
RES
Pin Name
I/O
I/O
I/O
¾
O
O
O
O
I
I
I
I
I
I
I
Crystal or
Pull-high
CMOS or
Pull-high
CMOS or
1/3 or 1/4
Wake-up
Option
or None
or None
NMOS
NMOS
Mask
Duty
RC
¾
¾
¾
¾
¾
¾
¾
¾
PA0~PA7 constitute an 8-bit bidirectional input/output port
with Schmitt trigger input capability. Each bit on port can be
configured as a wake-up input by mask option. PA0~PA3 can be
configured as a CMOS output or NMOS input/output with or
without pull-high resistor by mask option. PA4~PA7 are al-
ways pull-high NMOS input/output. Of the eight bits,
PA0~PA1 can be set as I/O pins or buzzer outputs by mask op-
tion. PA3 can be set as an I/O pin or as a PFD output also by
mask option.
PB0~PB7 constitute an 8-bit Schmitt trigger input port. Each
bit on port are pull-high resistor. Of the eight bits, PB0 and PB1
can be set as input pins or as external interrupt control pins
(INT0) and (INT1) respectively, by software application. PB2
and PB3 can be set as an input pin or as a timer/event counter
input pin TMR0 and TMR1 also by software application.
PC0~PC3 constitute a 4-bit bidirectional input/output port
with a schmitt trigger input capability. On the port, such can be
configured as CMOS output or NMOS input/output with or
without pull-high resistor by mask option.
Negative power supply, GND
LCD power supply
Voltage pump
SEG32 can be set as a segment or as a common output driver for
LCD panel by mask option. COM2~COM0 are outputs for LCD
panel plate.
LCD driver outputs for LCD panel segments
Real time clock oscillators
Positive power supply
OSC1 and OSC2 are connected to an RC network or a crystal
(by mask option) for the internal system clock. In the case of RC
operation, OSC2 is the output terminal for 1/4 system clock.
Schmitt trigger reset input, active low
6
Description
August 18, 1999
HT49C50