Cray CRAY-1 - Page 118

Hold issue conditions
f'\o reserved
P,i reserved
Block sequence flag set (034 - 037, 176, 177)
034 - 037 in process
Exchange in process
Scalar reference in
CP2
Rank B data valid
Fetch request
in last clock period
I/O memory request
Execution
time
For 034, 036:
Instruction issue 14 CPs + (Ai) if (Ai) r 0; 5 CPs if (Ai) = 0
For 035, 037:
Instruction issue 6 CPs + (Ai) if (Ai) r 0; 7 CPs if (Ai) = 0
Special cases
1. Block all issues when in process.
2. Block all I/O references.
3. An out-of-range memory reference will cause an interrupt condition
to occur.
For 034, 036, the interrupt will occur in 2 CP + 2 issues.
For 035, 037, the interrupt will occur in 0 to 2 CP + 2 issues.
4. For 034, 036, memory reference out of limits will allow two
parcels to issue. For 035, 037, two to four parcels will issue.
5. An uncorrected memory parity error will allow a minimum of 2
issues
and a maximum of 7 CPs + 2 issues.
6. (Ai) = 0 causes a zero block transfer.
200
8
> (Ai) > 100 causes a wrap-around condition
(Ai) > 177
8
,
bits 27 through 2
23
are truncated. The block
transfer is equal to the value of 2
0
through 26.
7. (Ao) is used as the block length if i = O.
2240004 4- 32 E