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I/O Signals:
Inputs:
Example:
Several bits such as Sign and Overrange can be combined into one
four line group to conserve data lines. Use jumpers to +5 Vdc and
to ground to convert a single line signal such as 'Polarity' into a four
bit value. See the sample cable in Section 2.9 for jumper examples.
Tie all unused data input lines to the logic '0' potential (If the inputs
are low true, leave the unused signals open. The 4863/2363's
internal pullup resistors will pull the signals to +5 V). Record the
signal names and pin numbers in your copy of Table 2-7 or 2-9.
If handshaking is enabled, record the external signal (and pin
number) that will be connected to the EDR input in Table 2-7. If
the 4863's Inhibit output is being used, record the signal name and
pin number in Table 2-7 or 2-9. In Table 2-8 record the number of
input bytes used, the data polarity, Talk handshaking enabled
status, EDR polarity and Inhibit polarity.
5.
If output data is being transferred by a string command, the output
data lines should be assigned next. Start with the lowest available
byte in Table 2-7 or 2-9. If the string data is HEX or BCD
characters, the lowest available nibble will be the MSN in the
output data. i.e. if 2 bytes were used in step 2, then MSN-4 becomes
the most significant digit in the output string. i.e. for an output
string of "1234", the "0001" code will appear on lines CH20-CH17.
Assign the signals to the proper bit weights so that the numbers
come out correctly for the external device. For binary data use the
binary bit weights. Record the device signal names and pin
numbers in Table 2-7 or 2-9. Leave the unused data lines open.
Record the bytes used and signal polarity in Table 2-8.
If the Output Data Strobe will be used, record the signal and pin
number in Table 2-7 or 2-9. Record strobe polarity in Table 2-8.
If Listen Handshaking is to be enabled, connect a signal to Status
A input in Table 2-7 or 2-9. In Table 2-8 record the Listen
Handshake enabled and the polarity of the Status Input when data
can be transferred.
CH4-1,
CH8-5, CH12-9, CH16-13
Sign/overrange, MSD,
+
2-33
MSD-1,
LSD
1
9
9
2
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