Ad = Insert (As, Im16 - Lucent Technologies DSP1617 Information Manual

Information Manual
April 1998

aD = insert (aS, IM16)

mask ← (1s in bits [OFFSET] thru [OFFSET + WIDTH]; other bits 0)
(aD) ← (((aS) << OFFSET) & mask) | ((a ) &
The low-order bits of the 36-bit aS register are inserted in an arbitrarily selected sequence of contiguous bits in a
(also 36-bit). Nonselected bits in aS are left unchanged. The merged result is then stored in aD.
This bit-field ina is defined by the 16-bit immediate value IM16. The upper eight bits of IM16 hold the WIDTH of S
the field (in bits), and the lower eight bits of IM16 hold the OFFSET from bit zero of a (in bits):
Bit
IM16
For example, IM16 = 0xe06 defines a 14-bit wide field, starting from bit six of a . This replaces bits 19—6 of a
with the low-order bits of aS (bits 13—0) and places the merged result into aD.
Flags are set based on the value written into aD. The LLV flag is set if WIDTH = 0 or if (WIDTH + OFFSET) > 36.
Bit
15 14
Field word1 1 1
word2
Lucent Technologies Inc.
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
(bit field insert with immediate control word)
S MASK
15—8
WIDTH
13 12 11 10
1 1 0 D
Words: 2
Cycles: 2
Group: BMU
Addressing: Immediate, Register
Flags affected: LMI, LEQ, LLV, LMV,
ODDP, EVENP, MNS1, NMNS1
Interruptible: Yes
Cacheable: No
Format: 3b
DRAFT COPY
)
9 8 7 6
S 1 1 1
Immediate Value (IM16)
Instruction Set Summary
S
7—0
OFFSET
S
5 4 3 2
0 0 1 0
S
S
1 0
0 0
B-54