78M6618 Data Sheet DS_6618_005
28 Rev. 1.4
4.3 Digital Pins
Table 28: Digital Pins
Name Type Circuit Description
COM1,COM0 O 5 LCD Common Outputs: These 2 pins provide the select signals for an
LCD display.
DIO3 I/O 3,4 Dedicated DIO pin.
SEG0…SEG2,
SEG7, SEG8
SEG12,
SEG14…SEG18
O 5
Dedicated LCD Segment Output pins.
SEG24/DIO4…
SEG31/DIO11,
SEG33/DIO13…
SEG39/DIO19,
SEG63/DIO43
I/O 3, 4, 5
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.
SEG3/PCLK
SEG4/PSDO
SEG5/PCSZ
SEG6/PSDI
I/O 3, 4, 5
Multi-use pins, configurable as either LCD SEG driver or SPI PORT.
E_RXTX/SEG9
I/O 1, 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_RST/SEG11 I/O 1, 4, 5
E_TCLK/SEG10 O 4, 5
ICE_E I 2
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.
CKTEST/SEG19,
MUXSYNC/SEG7
O 4, 5
Multi-use pins, configurable as either multiplexer/clock output or LCD
segment driver using the I/O RAM registers CKOUT_E or
MUX_SYNC_E.
TMUXOUT O 4
Digital output test multiplexer. Controlled by TMUX[3:0].
OPT_RX/DIO1 I/O 3, 4, 7
Multi-use pin, configurable as Optical Receive Input or general DIO.
When configured as OPT_RX, this pin receives 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.
OPT_TX/DIO2 I/O 3, 4
Multi-use pin, configurable as either optical LED transmit output,
WPULSE, RPULSE, or general DIO. When configured as OPT_TX,
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.
RESET I 2
Chip reset: This input pin is used to reset the chip into a known state.
For normal operation, this pin is pulled low. To reset the chip, this pin
should be pulled high. This pin has an internal 30 µA (nominal)
current source pull-down. No external reset circuitry is necessary.
RX I 3
UART input. If this pin is unused, it must be terminated to V3P3D
or GNDD.
TX O 4
UART output.
TEST I 7 Enables Production Test. This pin must be grounded in normal
operation.
Pin types: P = Power, O = Output, I = Input, I/O = Input/Output.
The circuit number denotes the equivalent circuit, as specified in Section 5 I/O Equivalent Circuits.
