tm1300 NXP Semiconductors, tm1300 Datasheet - Page 369

• Manufacturer Part Number: tm1300
• Description: Tm-1300 Media Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Sum of products of signed 16-bit halfwords
SYNTAX
FUNCTION
DESCRIPTION
halfwords of r src1 and r src2 ; the two products are summed, and the result is written to r dest . All values are considered
signed; thus, the intermediate products and the final sum of products are signed. All intermediate computations are
performed without loss of precision; the final sum of products is clipped into the range [0x80000000..0x7fffffff] before
being written into r dest .
modification of the destination register. If the LSB of r guard is 1, r dest is written; otherwise, r dest is not changed.
EXAMPLES
r30 = 0x00020003, r40 = 0x00010002
r10 = 0, r60 = 0xff9c0064, r70 = 0x0064ff9c
r20 = 1, r60 = 0xff9c0064, r70 = 0x0064ff9c
r30 = 0x00020003, r70 = 0x0064ff9c
As shown below, the
The
[ IF r guard ] ifir16 r src1 r src2
if r guard then
r src1
r dest
ifir16
3
sign_ext16to32(r src1 <31:16>)
sign_ext16to32(r src1 <15:0>)
signed
Initial Values
operation optionally takes a guard, specified in r guard . If a guard is present, its LSB controls the
ifir16
Full-precision
33-bit result
1
r dest
operation computes two separate products of the two pairs of corresponding 16-bit
3
3
signed
sign_ext16to32(r src2 <31:16>) +
sign_ext16to32(r src2 <15:0>)
ifir16 r30 r40
IF r10 ifir16 r60 r70
IF r20 ifir16 r60 r70
ifir16 r30 r70
r dest
0
Clip to [2
signed
signed
31
–1..–2
Operation
PRODUCT SPECIFICATION
r src2
31
3
]
r50
r100
signed
r80
r90
DSPCPU Operations for TM1300
0
0
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
ifir8ii ifir8ui ufir8uu
r50
no change, since guard is false
r90
r100
1
ATTRIBUTES
0x8
0xffffb1e0
SEE ALSO
0xffffff9c
ifir16
signed
Result
ifir16
dspmul
2, 3
No
93
—
0
2
3
A-83