MC2502 View Datasheet(PDF) - PMD
Part Name
Description
MFG CO.
'MC2502' PDF : 51 Pages View PDF
5.4.2 CP chip
Pin Name and Number Direction
~WriteEnbl 1
Output
R/~W
4
Output
~Strobe
6
Output
~PeriphSlct 130
Output
~RAMSlct
129
Output
~Reset
41
Input
W/~R
132 Output
SrlRcv
43
Input
SrlXmt
44
SrlEnable
99
~HostIntrpt 98
I/OIntrpt
53
Data0
9
Data1
10
Data2
11
Data3
12
Data4
15
Data5
16
Data6
17
Data7
18
Data8
19
Data9
22
Data10
23
Data11
24
Data12
25
Data13
26
Data14
27
Data15
28
Output
Output
Output
Input
Bi-
directional
CP chip
Description
When low, this signal enables data to be written to the bus.
This signal is high when the CP chip is performing a read, and low when it is
performing a write. It should be connected to I/O chip pin 53, CPR/~W.
This signal is low when the data and address are valid during CP
communications. It should be connected to I/O chip pin 54, CPStrobe.
This signal is low when peripheral devices on the data bus are being addressed. It
should be connected to I/O chip pin 52, CPPeriphSlct.
This signal is low indicates that external memory is being accessed.
This is the master reset signal. When brought low, this pin resets the chipset to its
initial conditions.
This signal is the inverse of R/~W; it is high when R/~W is low, and vice versa. For
some decode circuits, this is more convenient than R/~W.
This pin receives serial data from the serial transceiver.
NOTE! If this signal is not used, it should be tied high.
This pin transmits serial data to the asynchronous serial port.
This pin sets the serial port enable line. SrlEnable is always high for the point-to-
point protocol and is high during transmission for the multi-drop protocol.
When low, this signal causes an interrupt to be sent to the host processor.
This signal interrupts the CP chip when a host I/O transfer is complete. It
should be connected to I/O chip pin 77, CPIntrpt.
Multi-purpose data lines. These pins comprise the CP chip’s external data bus,
used for all communications with the I/O chip and peripheral devices such as
external memory or DACs. They may also be used for parallel-word input and
for user-defined I/O operations.
MC2502 Technical Specifications
33
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