W78E054D Datasheet, PDF (10/89 Pages) List of Unclassifed Manufacturers – 8-bit microcontroller

W78E054D/W78E052D Data Sheet
Pin Description, continued
SYMBOL TYPE DESCRIPTIONS
P3.0P3.7
P4.0P4.3
PORT 3: Port 3 is a bi-directional I/O port with internal pull-ups. All bits have al-
ternate functions, which are described below:
RXD (P3.0): Serial Port 0 input
TXD (P3.1): Serial Port 0 output
INT0 (P3.2) : External Interrupt 0
I/O H _{INT1 (P3.3) : External Interrupt 1}
T0 (P3.4) : Timer 0 External Input
T1 (P3.5) : Timer 1 External Input
WR _{(P3.6) : External Data Memory Write Strobe}
RD _{(P3.7) : External Data Memory Read Strobe}
PORT 4: Another bit-addressable bidirectional I/O port P4. P4.3 and P4.2 are
I/O H ^{alternative function pins. It can be used as general I/O port or external interrupt}
input sources ( INT2 / INT3 ).
* Note: TYPE I: input, O: output, I/O: bi-directional, H: pull-high, L: pull-low, D: open drain.
In application if MCU pins need external pull-up, it is recommended to add a pull-up resistor
(10K) between pin and power (V_DD) instead of directly wiring pin to V_DD for enhancing EMC.
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Publication Release Date: Jun 9, 2015
Revision A13