tm1300 NXP Semiconductors, tm1300 Datasheet - Page 371

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

Philips Semiconductors
Signed sum of products of unsigned/signed
bytes
SYNTAX
FUNCTION
DESCRIPTION
bytes of r src1 and r src2 ; the four products are summed, and the result is written to r dest . The bytes from r src1 are
considered unsigned, but the bytes from r src2 are considered signed; thus, the intermediate products and the final
sum of products are signed. All computations are performed without loss of precision.
modification of the destination register. If the LSB of r guard is 1, r dest is written; otherwise, r dest is not changed.
EXAMPLES
r70 = 0x0afb14f6, r30 = 0x0a0a1414
r10 = 0, r70 = 0x0afb14f6, r30 = 0x0a0a1414
r20 = 1, r80 = 0x649c649c, r40 = 0x9c649c64
r50 = 0x80808080, r60 = 0xffffffff
As shown below, the
The
[ IF r guard ] ifir8ui r src1 r src2
if r guard then
r src1
r dest
ifir8ui
3
unsigned
zero_ext8to32(r src1 <31:24>)
zero_ext8to32(r src1 <23:16>)
zero_ext8to32(r src1 <15:8>)
zero_ext8to32(r src1 <7:0>)
Initial Values
operation optionally takes a guard, specified in r guard . If a guard is present, its LSB controls the
2
unsigned
ifir8ui
1
unsigned
r dest
operation computes four separate products of the four pairs of corresponding 8-bit
3
sign_ext8to32(r src2 <7:0>)
sign_ext8to32(r src2 <31:24>) +
sign_ext8to32(r src2 <15:8>) +
7
sign_ext8to32(r src2 <23:16>) +
unsigned
ifir8ui r30 r70
IF r10 ifir8ui r30 r70
IF r20 ifir8ui r40 r80
ifir8ui r60 r50
0
r dest
signed
Operation
PRODUCT SPECIFICATION
r src2
3
signed
r90
r120
2
DSPCPU Operations for TM1300
r100
r110
signed
0
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
ifir8ii ufir8uu ifir16
r90
no change, since guard is false
r110
r120
1
signed
ATTRIBUTES
0xfa
SEE ALSO
0x2bc0
0xfffe0200
ufir16
Result
7
signed
ifir8ui
dspmul
2, 3
No
91
—
0
2
3
A-85