F1 Y = Y[L - Lucent Technologies DSP1617 Information Manual

Information Manual
April 1998

F1 Y = y[l]

(multiply/ALU operation with parallel store of y register)
perform operation F1 and
(*rM) ← (y) or (yl); then
modify rM
This instruction performs the following operations (effectively in parallel):
1. The operation F1 is performed. The possible operations for F1 are as follows:
F1 Operation
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. Write the value of y or yl to the Y-space location pointed to by rM where rM is specified by the two most sig-
nificant bits of the Y field:
00 - r0
The X field selects y or yl:
X = 0 → y
Lucent Technologies Inc.
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
F1 Operation
0110 nop
0111 aD = aS – p
1000 aD = aS | y
1001 aD = aS ^ y
1010 aS & y
Section 3.3, Arithmetic and
01 - r1
X = 1 → y
DRAFT COPY
Instruction Set Summary
F1
1011 aS – y
1100 aD = y
1101 aD = aS + y
1110 aD = aS & y
1111 aD = aS – y
Precision, for the options
10 - r2
Operation
11 - r3
B-34