em78p164n ELAN Microelectronics Corp, em78p164n Datasheet - Page 26

• Manufacturer Part Number: em78p164n
• Description: 8-bit Microcontroller With Otp Rom
• Manufacturer: ELAN Microelectronics Corp

EM78P164N
8-Bit Microcontroller with OTP ROM
20 •
5.4 I/O Ports
The I/O registers, both Port 5 and Port 6, are bidirectional tri-state I/O ports. Port 6 can
be pulled-high internally by software except P63. In addition, Port 6 can also have
open-drain output by software except P63. Input status changed interrupt (or wake-up)
function is available from Port 6. P53 ~ P50 and P62 ~ P60 pins can be pulled-down by
software. Each I/O pin can be defined as "input" or "output" pin by the I/O control
register (IOC5 ~ IOC6) except P63. The I/O registers and I/O control registers are both
readable and writable. The I/O interface circuits for Port 5 and Port 6 are shown in
Figure 5-5, Figure 5-6 and Figure 5-7 respectively.
Note: Pull-down is not shown in the figure.
PORT
Figure 5-5 The Circuit of I/O Port and I/O Control Register for Port 5
0
1
M
U
X
(This specification is subject to change without further notice)
Q
Q
Q
Q
_
PCRD
_
C
P
R
L
P
R
C
L
CLK
CLK
Product Specification (V1.4) 05.28.2010
D
D
PDRD
PDWR
PCWR
IOD