HT46RU66/HT46CU66
Pin Description
Configuration
Option
Pin Name
I/O
Description
Bidirectional 8-bit input/output port. Each individual pin on this port can
be configured as a wake-up input by a configuration option. Software in-
structions determine if the pin is a CMOS output or Schmitt Trigger input.
Configuration options determine which pins on the port have pull-high
resistors. Pins PA0, PA1 and PA3 are pin-shared with BZ, BZ and PFD
respectively, the function of which is chosen via configuration options.
PA0/BZ
Pull-high
Wake-up
Buzzer
PFD
PA1/BZ
PA2
I/O
PA3/PFD
PA4~PA7
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. PB is
pin-shared with the A/D input pins. The A/D inputs are selected via soft-
ware instructions. Once selected as an A/D input, the I/O function and
pull-high resistor functions are disabled automatically.
PB0/AN0~
PB7/AN7
I/O
I/O
Pull-high
Pull-high
Bidirectional 8-bit input/output port. Software instructions determine if
the pin is a CMOS output or Schmitt Trigger input. A Configuration option
determines if the port has pull-high resistors. Pin PC0 is pin-shared with
the timer input pin TMR2. Pins PC6 and PC7 are pin-shared with the
UART pins TX and RX.
PC0/TMR2
PC1~PC5
PC6/TX
PC7/RX
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. PD0~PD3 are
pin-shared with PWM0~PWM3, the function of each pin is selected via a
configuration option. Pins PD4 and PD5 are pin-shared with external in-
terrupt input pins INT0 and INT1 respectively. Configuration options de-
termine the interrupt enable/disable and the interrupt low/high trigger
type. Pins PD6 and PD7 are pin-shared with the external timer input pins
TMR0 and TMR1 respectively.
PD0/PWM0
PD1/PWM1
PD2/PWM2
PD3/PWM3
PD4/INT0
Pull-high
PWM
I/O
Interrupt
PD5/INT1
PD6/TMR0
PD7/TMR1
OSC1 and OSC2 are connected to an external RC network or external
crystal, determined by configuration option, for the internal system clock.
For external RC system clock operation, OSC2 is an output pin where
the system frequency can be monitored, at a frequency of 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.
OSC1
OSC2
I
Crystal or RC
O
OSC3
OSC4
I
RTC or
OSC3 and OSC4 are connected to a 32768Hz crystal to form a real time
clock for timing purposes or to form a system clock.
O
System Clock
VLCD
LCD power supply
¾
¾
IC maximum voltage, connect to VDD, VLCD or V1
LCD voltage pump
VMAX
¾
¾
¾
V1, V2, C1, C2
I
LCD driver outputs for LCD panel segments. A configuration option can
select all pins to be used as segment drivers or all pins to be used as
CMOS outputs.
SEG0~SEG7 or
CMOS output
SEG0~SEG7
SEG8~SEG15
O
O
LCD driver outputs for LCD panel segments. A configuration option can
select all pins to be used as segment drivers or all pins to be used as
CMOS outputs.
SEG8~SEG15 or
CMOS output
LCD driver outputs for LCD panel segments. Configuration options can
select each pin to be used as either a segment driver or each pin to be
used as a CMOS output.
SEG16~SEG23
CMOS output
SEG16~SEG23
SEG24~SEG45
O
O
O
LCD driver outputs for LCD panel segments
¾
An LCD duty-cycle configuration option determines if SEG46 is config-
ured as a segment driver or as a common output driver for the LCD
panel. COM0~COM2 are the LCD common outputs.
COM0~COM2
COM3/SEG46
1/3 or 1/4 Duty
COM3 or SEG46
Rev. 1.20
4
October 2, 2007
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
