PNX1301 PHILIPS [NXP Semiconductors], PNX1301 Datasheet - Page 325

• Manufacturer Part Number: PNX1301
• Description: Media Processors
• Manufacturer: PHILIPS [NXP Semiconductors]

PNX1300/01/02/11 Data Book
dspidualmul
SYNTAX
FUNCTION
DESCRIPTION
pairs of high and low 16-bit halfwords of rsrc1 and rsrc2. Both products are clipped into the range [2
[0x7fff..0x8000]) and written into the corresponding halfwords of rdest. All values are signed 16-bit integers.
the modification of the destination register. If the LSB of rguard is 1, rdest is written; otherwise, rdest is not changed.
EXAMPLES
A-27
r30 = 0x0020010, r40 = 0x00030020
r10 = 0, r30 = 0x0020010, r40 = 0x00030020
r20 = 1, r30 = 0x0020010, r40 = 0x00030020
r50 = 0x80000002, r80 = 0x00024000
r110 = 0x08000003, r120 = 0x00108001
As shown below, the
The
[ IF rguard ] dspidualmul rsrc1 rsrc2
if rguard then {
}
32-bit signed products
rsrc1
temp1
temp2
if temp1 < 0xffff8000 then temp1
if temp2 < 0xffff8000 then temp2
if temp1 > 0x7fff then temp1
if temp2 > 0x7fff then temp2
rdest<31:16>
rdest<15:0>
Two full-precision
dspidualmul
31
31
sign_ext16to32(rsrc1<15:0>)
sign_ext16to32(rsrc1<31:16>)
Initial Values
signed
temp1<15:0>
temp2<15:0>
dspidualmul
PRELIMINARY SPECIFICATION
operation optionally takes a guard, specified in rguard. If a guard is present, its LSB controls
Clip to [2
15
rdest
signed
0x7fff
0x7fff
15
–1..–2
0x8000
0x8000
31
signed
operation computes two 16-bit clipped, signed products separately on the two
Dual clipped multiply of signed 16-bit halfwords
sign_ext16to32(rsrc2<15:0>)
15
sign_ext16to32(rsrc2<31:16>)
dspidualmul r30 r40
IF r10 dspidualmul r30 r40
IF r20 dspidualmul r30 r40
dspidualmul r50 r80
dspidualmul r110 r120
]
signed
0
0
rdest
15
Operation
31
rsrc2
31
signed
r60
r90
signed
r125
Clip to [2
signed
0
r70
r100
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
15
dspidualabs dspidualadd
–1..–2
dspidualsub dspiabs
Philips Semiconductors
15
15
r60
no change, since guard is false
r100
r90
r125
]
ATTRIBUTES
SEE ALSO
0x00060200
0x80007fff
0x00060200
0x7fff8000
signed
Result
15
–1..–2
0
dspmul
2, 3
No
95
—
0
2
3
15
] (or