CD Field
10 IBM Confidential
Specifies the destination for the ALU output.
CD
=
0000 (Z)
This specifies no destination, and allows an ALU function where an output
zero test is desired without changing the data held in the registers. (See
example
9A,
page 25.)
CD
=
0001
(TE)
This specifies the 1050 buss out (TE) as the destination for the ALU out-
put.
CD
=
0010
(JE)
This specifies the direct data channel buss out (JE) as the destination for
the D register output (complement), and not the normal ALU output.
CD
=
0011 (Q)
This specifies the memory protect register
(Q)
as the destination for the
ALU output.
CD
=
0100 (TA)
This specifies the 1050 tags out (TA) as the destination for the ALU out-
put.
CD
=
0101 (H)
This specifies the hold register (H) as the destination for the ALU output.
CD
=
0110 (5)
This specifies the S register as the destination for the ALU output.
CD
=
0111
(R)
This specifies the R register as the destination for the ALU output. The
*
denotes the time in a read-compute-write sequence that R may be desig-
nated as a destination. (See example 9B, pages 25 and 26.)
*
Read - Compute - Write
*
Read-Store
Read-Write
* *
Read - Compute - Compute - Write
* *
Read - Compute - Compute - Read (Dummy)
*
Compute - Write
CD
=
1000 (D)
This specifies the D register as the destination for the ALU output.
CD = 1001 (L)
This specifies the L register as the destination for the ALU output.
CD
=
1010 (G)
This specifies the OP register (G) as the destination for the ALU output.
CD
=
1011
(T)
This specifies the T register as the destination for the ALU output.
CD
=
1100 (V)
This specifies the V register as the destination for the ALU output.
CD
=
1101 (U)
This specifies the U register as the destination for the ALU output.
CD
=
1110 (J)
This specifies the J register as the destination for the ALU output.

CF Field
CG Field
CY Field
CD
=
IIII
(I)
This specifies the I register as the destination for the ALU output.
This field controls the ALU-A register entry for High-Low 4 bit gating
and straight crossed switching.
CF
=
0000 (0)
This specifies the ALU-A register entry will be blocked and forced to
zeros. (See example lOA, page 26.)
CF
=
0001 (L)
This specifies the ALU-A register entry Low 4 bits will be gated and the
High 4 bits will be blocked and forced to zeros. (See example lOA, page 26.)
OF
~
0010 (H)
This specifies the ALU-A register entry High 4 bits will be gated and the
Low 4 bits will be blocked and forced to zeros. (See example lOA, page 26.)
CF
=
0011 (Straight)
This specifies the AL U-A register entry High and Low 4 bits will be gated.
(See example lOA, page 26.)
CF
=
0100 (Stop)
This specifies a machine stop function. The machine stops at the end of the
cycle prior to the microword containing this instruction. The WX register
contains the address of this microword.
OF
=
0101 (XL)
This specifies the ALU-A register entry will cross the High 4 bits into the
Low 4 bits and the Low 4 bits into the High 4 bits. Then it gates the Low 4
bits to the ALU and blocks the High 4 bits, forcing them to zeros. (See ex-
ample lOB, page 26.)
CF
=
0110 (XH)
This specifies the ALV-A register entry will cross the High 4 bits into the
Low 4 bits and the Low 4 bits into the High 4 bits.
It
then gates the High 4
bits to the ALU and blocks the Low 4 bits, forcing them to zeros. (See ex-
ample lOB, page 26.)
CF
=
0111 (X)
This specifies the ALU-A register entry will cross the High 4 bits into the
Low 4 bits and the Low 4 bits into the High 4 bits. Then both the High and
Low 4 bits are gated to the ALU. (See example lOB, page 26.)
This field controls the ALU-B entry High-Low 4 bit gating.
CG
=
0000 (0)
This specifies the ALU-B register entry will be blocked and forced to
zeros. (See example 11, page 27.)
CG
=
0001 (L)
This specifies the ALU-B register entry Low 4 bits will be gated, and the
High 4 bits will be blocked and forced to zeros. (See example 11, page 27.)
CG
=
0010 (H)
This specifies the ALU-B register entry High 4 bits will be gated, and the
Low 4 bits will be blocked and forced to zeros. (See example 11, page 27.)
This field controls the ALU true-complement and binary-decimal functions.
CY
=
0000
(+)
This specifies a true binary add.
IBM Con/iJentitll
11