Cray CRAY-1 - 16-Bit High-Speed Asynchronous Input Channel Signal Exchange

I
Table 6-4. 16-bit high-speed asynchronous input channel signal exchange
(ON module)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
CRAY-1
Activate
channel
(set CL and CA)
Resume
•
Resume
.-
Resume
~
Resume
~
...
External
If done, go to 11.
Data
Data
2
63
_
247_
2
48
with Ready
2
32
with Ready
Data
2
31
_
... 2
16
with Ready
Data
2
15
_
~ 2° with Ready
Write word to memory and advance current address; go to 2.
... Disconnect
Set interrupt and deactivate channel.
Bit assignments are
as follows:
Parity Bit 0 Data Bi ts
2
0
-
23
Parity Bit 1
Data
Bi ts
24 -
27
Parity Bit 2
Data
Bits
2
8
-
211
Parity Bit 3 Data Bi ts
212 - 215
Parity bits are sent
from the external device to the CRAY-1 at the
same time as the data- bits.
They are held stable in the same way as
are the data bits.
Ready - The Ready signal sent to the CRAY-1 indicates that data will
soon be sent to the CRAY-1 input channel and may be sampled. The
Ready signal is a pulse 50 ± 10 nanoseconds wide (at the 50% voltage
points)
sent in groups of four. The leading edge of Ready at the
CRAY-1 begins the timing for sampling the data bits.
The time from the leading edge of one Ready pulse to the leading edge
of the following Ready pulse in the same group must be greater than
90 nsec. The first Ready pulse of a group may be transmitted by the
device
as soon as it detects the leading edge of the first Resume
pulse for that group.
2240004
6-11
E