Pin Assignment
Pin Description
Pin Name
I/O
Code
Option
Description
PA0~PA7
I/O
Bidirectional 8-bit input/output port with pull-high resistors. Each bit can be de-
termined as NMOS output or Schmitt trigger input by software instructions.
PB0, PB1
I/O
Wake-up
or None
2-bitbidirectionalinput/outputlineswithpull-highresistors.Eachbitcanbede-
termined as NMOS output or Schmitt trigger input by software instructions.
Each bit can also be configured as wake-up input by code option.
PB2~PB5
I
Wake-up or
None
4-bit Schmitt trigger input lines with pull-high resistors. Each bit can be config-
ured as a wake-up input by code option.
PC0/REM
O
Level or
Carrier
Level or carrier output pin
PC0 can be set as CMOS output pin or carrier output pin by code option.
VDD
Positive power supply
VSS
Negative power supply, ground
OSC2
OSC1
O
I
Crystal
or RC
OSC1, OSC2 are connected to an RC network or a crystal (determined by
code option) for the internal system clock. In the case of RC operation, OSC2
is the output terminal for 1/4 system clock (NMOS open drain output).
RES
I
Schmitt trigger reset input. Active low.
Absolute Maximum Ratings
Supply Voltage...........................V
SS
0.3V to V
SS
+4.0V
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 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 reliabil-
ity.
HT48RA0-2/HT48CA0-2
Rev. 1.50
2
July 23, 2004
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