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.
P4.0
23
34
1
17
28
39
6
BU Port4 is extended I/O ports such like Port1. It can
be available only on 44L-PLCC and 44L-PQFP
package.
P4.1
P4.2 (/INT3)
P4.3 (/INT2)
RESET
12
10
9
4
IS A high on this pin for at least two machine cycles
will reset the device.
ALE
30
29
31
33
32
35
27
26
29
O
O
I
Output pulse for latching the low byte of address
during accesses to external memory.
/PSEN
/EA
The read strobe to external program memory, low
active.
EA must be kept at low to enable the device to
fetch program code from external flash memory.
An internal pull-up resistance has been
embedded in this pin.
XTAL1
XTAL2
VDD
19
18
40
20
21
20
44
22
15
14
38
16
I
Input to the inverting oscillator amplifier.
Output from the inverting amplifier.
Power Supply
O
P
G
VSS
Ground
MEGAWIN
MPC89x515A Data Sheet
5
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
