F1 Z : Y[L - Lucent Technologies DSP1617 Information Manual

Information Manual
April 1998

F1 Z : y[l]

(multiply/ALU operation with compound data move)
perform operation F1 and in parallel, perform the following compound data move:
temp ← (y) or (yl); then
(y) or (yl) ← (*rM); then
modify rM (first action); then
(*rM) ← temp; then
modify rM (second action)
This instruction performs the following operations effectively in parallel:
1. The operation F1 is performed. The possible F1 operations are as follows:
F1
0000 aD = pp = x * y
0001 aD = aS + pp = x * y
0010 p = x * y
0011 aD = aS – pp = x * y
0100 aD = p
0101 aD = aS + p
The value of S can be zero to select a0 or one to select a1. The value of D can be zero to select a0 or one to
select a1. Flags are modified based on the value computed by the DAU.
Note: For all diadic operations involving the y register, y is sign-extended to 36 bits before performing the
operation (including logical operations). (See
available when shifting the output of the p register into aS in the above operations.)
2. Save either the y or yl register into an internal temporary location (temp). The X field selects y or yl:
X = 0 → yl
3. Access the Y-space location pointed to by rM, and write this value into the y (or yl) register. rM is specified by
the two most significant bits of the Z field:
00 - r0
4. Postmodify the value of rM using the first action described by the two least significant bits of the Z field
described below.
Lucent Technologies Inc.
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
Operation
0110
0111
1000
1001
1010
X = 1 → y
01 - r1
DRAFT COPY
F1 Operation
nop
aD = aS – p
aD = aS | y
aD = aS ^ y
aS & y
Section 3.3, Arithmetic and
10 - r2
Instruction Set Summary
F1 Operation
1011 aS – y
1100 aD = y
1101 aD = aS + y
1110 aD = aS & y
1111 aD = aS – y
Precision, for the options
11 - r3
B-36