Rainbow Electronics HT49R70A-1 - Manual (Page 4)

Pin Description
Pin Name I/O Options Description
PA0/BZ
PA1/BZ
PA2
PA3/PFD
PA4~PA7
I/O
Wake-up
Pull-high
or None
CMOS or
NMOS
PA0~PA7 constitute an 8-bit bidirectional input/output port with Schmitt trig-
ger input capability. Each bit on port can be configured as a wake-up input by
options. PA0~PA3 can be configured as a CMOS output or NMOS input/out-
put with or without pull-high resistor by options. PA4~PA7 are always
pull-high NMOS input/output. Of the eight bits, PA0~PA1 can be set as I/O
pins or buzzer outputs by options. PA3 can be set as an I/O pin or as a PFD
output also by options.
PB0/INT0
PB1/INT1
PB2/TMR0
PB3/TMR1
PB4~PB7
I ¾
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 ap-
plication. 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~PC7 I/O
Pull-high
or None
CMOS or
NMOS
PC0~PC7 constitute an 8-bit bidirectional input/output port with a Schmitt trig-
ger input capability. On the port, such can be configured as CMOS output or
NMOS input/output with or without pull-high resistor by options.
VSS ¾ ¾ Negative power supply, ground
VLCD I ¾ LCD power supply
V1,V2,C1,C2 I ¾ Voltage pump
SEG40/COM3
COM2~COM0
O 1/3 or 1/4 Duty
SEG40 can be set as a segment or as a common output driver for LCD panel
by options. COM2~COM0 are outputs for LCD panel plate.
SEG39~SEG0 O ¾ LCD driver outputs for LCD panel segments
OSC4
OSC3 O
I
RTC or
System Clock
Real time clock oscillators. OSC3 and OSC4 are connected to a 32768Hz
crystal oscillator for timing purposes or to a system clock source (depending
on the options).
No built-in capacitor
VDD ¾ ¾ Positive power supply
OSC2
OSC1 O
I
Crystal or RC
OSC1 and OSC2 are connected to an RC network or a crystal (by options) for
the internal system clock. In the case of RC operation, OSC2 is the output ter-
minal for 1/4 system clock.
The system clock may come from the RTC oscillator. If the system clock co-
mes from RTCOSC, these two pins can be floating.
RES I ¾ Schmitt trigger reset input, active low
Absolute Maximum Ratings
Supply Voltage ...................................V
SS
-0.3V to 5.5V
Storage Temperature ............................ -50°C to 125°C
Input Voltage..............................V
SS
-0.3V to V
DD
+0.3V Operating Temperature........................... -40°C to 85°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.
HT49R70A-1
Rev. 1.00 4 December 4, 2001