Acer Laboratories Inc.
--Proprietary, Confidential, Preliminary--
M6759: 8 bit MTP Micro-controller
Ver. 1.01, Document Number : 6759DS02.doc
Page 5
Acer Labs: 11F, no. 45 Tung Hsing Road, Taipei 110, Taiwan, R.O.C. Tel: 886-2-8768-2800 Fax: 886-2-8768-3030
Homepage : www.ali.com.tw
2.2 Pin Description Table:
Pin assignments shown below are listed based on 44-pin PLCC package. And if not additionally specified,
further pin number reference throughout this datasheet is, by default, referred to 44-pin PLCC package. As
for the QFP package, the pin number assignment should be shifted accordingly, as comparatively shown
in Section 2.1 Pinout Diagram.
Pin Name
No. (PLCC)
Type
Description
VDD
44
IN
Power supply for internal operation, 5V input.
GND
22
IN
Ground.
P0.7-P0.0
36,37,38,39,
40,41,42, 43
I/O
Port 0 is 8 bits bi-directional I/O port with internal pull high.
AD7-0
Multiplexed address/data bus. During the time when ALE is high, the LSB of a
memory address is presented.
When ALE falls, the port transitions to a bi-
directional data bus. This bus is used to read external ROM and read/write external
RAM memory or peripherals.
RST
10
IN
Reset signal of internal circuit, it must be kept 4 clocks to ensure being recognized
by internal circuit. This signal will not affect internal SRAM.
XTAL1
21
IN
Crystal In, can be used as external clock input.
XTAL2
20
OUT
Crystal out, feedback of XTAL1.
/PSEN
32
OUT
Program Store Enable Output, commonly connected to external ROM memory as
a chip enable during fetching and MOVC operation. /PSEN goes high during a reset
condition.
ALE
33
OUT
Address Latch Enable, used to latch external LSB 8 bit address bus from
multiplexed address/data bus, commonly connect to the latch enable of 373 family.
This signal will be forced high when the device is in a reset condition.
P1.7-P1.0
9,8,7,6,5,4,3
,2
I/O
Port 1 is 8 bits bi-directional I/O port with internal pull high. All pins have an
alternate function shown as below.
T2EX (P1.1)
IN
External timer/counter 2 trigger.
T2 (P1.0)
IN
External timer/counter 2.
P2.7-P2.0
31,30,29,28,
27,26,25, 24
I/O
Port 2 is 8 bits bi-directional I/O port with internal pull high. The alternate function is
MSB 8 bit address bus
A15-A8
OUT
This bus emits the high-order address byte during fetches from external Program
Memory or during accesses to external Data Memory that use 16-bit addresses
(MOVX @ DPTR).
During accesses to external Data Memory that use 8-bit addresses (MOVX @ Ri),
Port 2 emits the contents of the P2 Special Function Register.
P3.7-P3.0
19,18,17,16,
15,14,13, 11
I/O
Port 3 is an 8-bit bi-directional I/O port with internal pull high. The reset condition of
this port is with all bits at a logic 1.
Port 3 also have alternate function list below
/RD (P3.7)
OUT
External data memory read strobe.
/WR (P3.6)
OUT
External data memory write strobe.
T1 (P3.5)
IN
External timer/counter 1.
T0 (P3.4)
IN
External timer/counter 0.
/INT1 (P3.3)
IN
External interrupt 1 (Negative Edge Detect).
/INT0 (P3.2)
IN
External interrupt 0 (Negative Edge Detect).
TXD (P3.1)
OUT
Serial port output.
RXD (P3.0)
IN
Serial port input.
/EAVPP
35
IN
The pin must be externally held low to enable the device to fetch code from external
program memory.
If /EAVPP is held high, the device executes from internal
program memory. /EAVPP is internal latched on reset. This pin also receives the
12V programming voltage (VPP) during FLASH programming.
NC
1,12,23,34
NC
These pins should not be connected for any purpose