Features
1.2
Pin Definitions and Functions
Pin Definitions and Functions
Pin No.
P-LCC-44
Pin No.
P-DIP-28
Symbol
Input (I)
Output (O)
Open
Drain (OD)
I/O
Function
4
3
1
44
42
41
39
38
13
12
9
5
2
43
35
17
8
3
2
1
28
27
26
25
24
-
-
-
-
-
-
-
11
5
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
A0
A1
A2
A3
A4
A5
A6
CS
WR
Address Data Bus.
If the multiplexed
address/data
µP
interface bus mode is
selected these lines transfer data and
commands between the
µP
and the IDEC.
If a demultiplexed mode is used, these lines
interface with the system data bus.
I
Address Bus.
These inputs interface to the
system´s address bus to select an internal
register for a read or write access. Only
provided in the P-LCC package and only
active if a demultiplexed
µP
interface is
selected.
Chip Select.
A low on this line selects the
IDEC for a read/write operation.
Write.
This signal indicates a write
operation, active low (Siemens/Intel bus
mode).
Read/Write.
At "high", identifies a valid
µP
access as a read operation. At "low",
identifies a
µP
access as a write operation
(Motorola bus mode). Only provided in the
P-LCC package.
Read.
This signal indicates a read operation,
active low (Siemens/Intel bus mode).
Data Strobe.
The rising edge marks the end
of a valid read or write operation (Motorola
bus mode). Only provided in the P-LCC
package.
I
I
8
-
R/W
I
7
4
RD
I
7
-
DS
I
Semiconductor Group
6
ETC [ ETC ]
