mpc89x54a Megawin Technology, mpc89x54a Datasheet - Page 6

• Manufacturer Part Number: mpc89x54a
• Description: 8-bit Micro-controller
• Manufacturer: Megawin Technology

6
P3.5 (T1)
P3.6 (/WR)
P3.7 (/RD)
P4.0
P4.1
P4.2 (/INT3)
P4.3 (/INT2)
RESET
ALE
/PSEN
/EA
XTAL1
XTAL2
VDD
VSS
15
16
17
30
29
31
19
18
40
20
9
44
17
18
19
23
34
12
10
33
32
35
21
20
22
1
MPC89x54A Data Sheet
12
13
17
28
39
27
29
15
14
38
16
11
26
6
4
BU Port4 is extended I/O ports such like
IS
O
O
O
G
P
I
I
keep the port high. Port3 also serves
other special functions of this device.
P3.0 and P3.1 act as receiver and
transceiver of the data for UART function
block,
Alias RXD and TXD.
P3.2 and P3.3 also act as external
interrupt sources, alias INT0 and INT1.
P3.4 and P3.5 also act as event sources
for timer0 and timer1 individually, alias
T0 and T1.
P3.6 also acts as write signal while
access to external memory, alias /WR.
P3.7 also acts as read signal while
access to external memory, alias /RD.
Port1. It can be available only on
44L-PLCC and 44L-PQFP package.
machine cycles will reset the device.
Output pulse for latching the low byte of
address during accesses to external
memory.
memory, low active.
device to fetch program code from
external flash memory.
An internal pull-up resistance has been
embedded in this pin.
Input to the inverting oscillator amplifier.
Output from the inverting amplifier.
Power Supply
Ground
A high on this pin for at least two
The read strobe to external program
EA must be kept at low to enable the
MEGAWIN