Cray CRAY-1 - Branch Format; Format for Memory Transfer Instructions; Two-Parcel Format for Branch Instructions

I
..
22
32 BITS
A ..... MEMORY
OPERATION
CODE
S .... MEMORY
~
ADDRESS
INDEX
REG.
RESULT (OR SOURCE)
REG.
ADDRESS
Figure 4-5. Format for memory transfer instructions
BRANCH FORMAT
In general, the branch instructions are two-parcel instructions. A 7-bit
operation code (gh) is followed by a 25-bit field formed by combining i, j,
k, and m. The 25-bit field contains a parcel address and allows branching
to a quarter-word boundary.
The 3-bit i field is unused. A program range
error occurs if either of the two low-order bits of i is set; the high-
order
bit of i is ignored.
Figure 4-6
illustrates the two-parcel format for branch instructions.
9
h k
m
4
I
3
!
23
2
I
32 BITS
1
1
BRANCH
t
OPERATION
CODE
ADDRESS
PARCEL
SELECT
Figure 4-6. Two-parcel format for branch instructions
2240004
4-4
E