DS_6612_001
78M6612 Data Sheet
7.3 Digital Pins
Name
Type Circuit Description
COM3,
COM2,
COM1,
COM0
LCD common outputs: These four pins provide the select signals for the LCD
display.
O
O
5
5
Dedicated LCD segment output pins. SEG 14 and SEG15 are only
available on the 68-pin package.
SEG0…SEG18
Multi-use pins, configurable as either LCD SEG driver or DIO. (DIO4 = SCK,
DIO5 = SDA when configured as EEPROM interface, WPULSE = DIO6,
VARPULSE = DIO7 when configured as pulse outputs). If unused, these
pins must be configured as DIOs and set to outputs by the firmware.
SEG24/DIO4…
SEG31/DIO11
I/O
3, 4, 5
SEG34/DIO14
…
SEG37/DIO17,
SEG39/DIO19,
SEG40/DIO20
Multi-use pins, configurable as either LCD SEG driver or DIO. If unused,
these pins must be configured as DIOs and set to outputs by the
firmware.
I/O
I/O
3, 4, 5
Multi-use pins, configurable as LCD driver or DIO (QFN 68 package only). If
3, 4, 5 unused, this pin must be configured as a DIO and set to an output by
SEG41/DIO21
the firmware.
E_RXTX/SEG38
E_RST/SEG32
I/O
O
1, 4, 5
4, 5
Multi-use pins, configurable as either emulator port pins (when ICE_E pulled
high) or LCD SEG drivers (when ICE_E tied to GND).
E_TCLK/SEG33
ICE enable. When zero, E_RST, E_TCLK, and E_RXTX become SEG32,
SEG33, and SEG38 respectively. For production units, this pin should be
pulled to GND to disable the emulator port. This pin should be brought out to
the programming interface in order to create a way for reprogramming parts
that have the SECURE bit set.
ICE_E
I
2
Multi-use pin, configurable as either Clock PLL output or LCD segment
driver. Can be enabled and disabled by CKOUT_E[1:0].
CKTEST/SEG19
TMUXOUT
O
O
4, 5
4
Digital output test multiplexer. Controlled by TMUX[4:0].
Multi-use pin, configurable as UART1 Input or general DIO. When con-
figured as RX1, this pin can optionally receive a signal from an external
photo-detector used in an IR serial interface. If unused, this pin must be
terminated to V3P3D or GNDD, or configured as a DIO and set to an
output by the firmware.
RX1/DIO1
TX1/DIO2
I/O
I/O
3, 4, 7
3, 4
Multi-use pin, configurable as a transmit output from UART1 (or optionally an
Optical LED Transmit Output), WPULSE, RPULSE, or general DIO. When
configured as TX1, this pin is capable of directly driving an LED for
transmitting data in an IR serial interface. If unused, this pin must be left
open, or configured as a DIO and set to an output by the firmware.
DIO pin (QFN 68 package only)
DIO3
I/O
I
3, 4
3
This input pin resets the chip into a known state. For normal operation, this
pin is connected to GNDD. To reset the chip, this pin should be pulled high.
No external reset circuitry is necessary. Direct connect to ground in normal
operation.
RESET
UART input. If unused, this pin must be terminated to V3P3D or GNDD.
UART output.
RX0
TX0
I
O
I
3
4
7
Enables Production Test. Must be grounded in normal operation.
TEST
Pin types: P = Power, O = Output, I = Input, I/O = Input/Output
The circuit number denotes the equivalent circuit, as specified on the following page.
Rev. 1.2
107