HT46R4A
Pin Description
Configuration
Pin Name I/O
Description
Option
PA0~PA2
PA3/PFD
Bidirectional 8-bit input/output port. Each individual pin on this port can be config-
ured as a wake-up input by a configuration option. Software instructions deter-
mine if the pin is a CMOS output or Schmitt Trigger input. Configuration options
Pull-high
Wake-up
PA4/TMR0
I/O
PA5/INT
PA3 or PFD determine which pins on the port have pull-high resistors. Pins PA3, PA4, PA7
and PA5 are pin-shared with PFD, TMR0, TMR1 and INT, respectively.
PA6
PA7/TMR1
PB0/AN0
PB1/AN1
PB2/AN2
Bidirectional 8-bit input/output port. Software instructions determine if the pin is a
CMOS output or Schmitt Trigger input. Configuration options determine which
PB3/AN3
PB4/AN4
PB5/AN5
PB6~PB7
I/O
I/O
Pull-high
pins on the port have pull-high resistors. PB is pin-shared with the A/D input pins.
The A/D inputs are selected via software instructions. Once selected as an A/D in-
put, the I/O function and pull-high resistor options are disabled automatically.
Bidirectional 8-bit input/output port. Software instructions determine if the pin is a
CMOS output or Schmitt Trigger input. Configuration options determine which
pins on the port have pull-high resistors.
PC0~PC7
Pull-high
Pull-high
Bidirectional 3-bit input/output port. Software instructions determine if the pin is a
CMOS output or Schmitt Trigger input. Configuration option determines which
PD0/PWM0
PD1/PWM1 I/O
PD2
I/O or PWM pins on the port have pull-high resistors. The PWM outputs are pin-shared with
pins PD0 and PD1 selected via configuration options.
OSC1, OSC2 are connected to an external RC network or external crystal, deter-
OSC1
OSC2
I
mined by configuration option, for the internal system clock. If the RC system
Crystal or RC
O
clock option is selected, pin OSC2 can be used to measure the system clock at
1/4 frequency.
RES
VDD
VSS
I
Schmitt Trigger reset input. Active low.
Positive power supply
¾
¾
¾
¾
¾
Negative power supply, ground
Note: 1. Each pin on PA can be programmed through a configuration option to have a wake-up function.
2. Individual pins can be selected to have a pull-high resistor.
3. Pins PC5~PC7 and pin PD2 exist but are not bounded out on the 28-pin package.
4. Unbounded pins should be setup as outputs or as inputs with pull-high resistors to conserve power.
Absolute Maximum Ratings
Supply Voltage...........................VSS-0.3V to VSS+6.0V
Input Voltage..............................VSS-0.3V to VDD+0.3V
Storage Temperature............................-50°C to 125°C
Operating Temperature...........................-40°C to 85°C
IOH Total............................................................-100mA
I
OL Total ..............................................................150mA
Total Power Dissipation .....................................500mW
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 reliability.
Rev. 1.00
3
November 28, 2007
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
