W79E648 Datasheet, PDF (5/80 Pages) Winbond – Fast 8051 Compatible microcontroller with a redesigned Processor

Preliminary W79E648
Pin Description, continued
SYMBOL
TYPE
DESCRIPTIONS
PORT 3: Port 3 is a bi-directional I/O port with internal pull-ups. All bits have
alternate 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
P3.0 − P3.7 I/O _{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: Port 4 is a 4-bit bi-directional I/O port. The P4.3 also provide the
P4.0 − P4.3 I/O
alternate function REBOOT which is H/W reboot from LD flash.
P5.0 – P5.7 I/O PORT 5: Port 5 is a bi-directional I/O port with internal pull-ups.
P6.0 – P6.7 I/O PORT6: Port 6 is a bi-directional I/O port with internal pull-ups.
P7.0 – P7.7 I/O PORT 7: Port 7 is a bi-directional I/O port with internal pull-ups.
* Note: TYPE I : input, O: output, I/O: bi-directional.
Publication Release Date: 05/31/2004
-5-
Revision A1