PNX1301EH/G,557 Trident Microsystems, Inc., PNX1301EH/G,557 Datasheet - Page 384

• Manufacturer Part Number: PNX1301EH/G,557
• Manufacturer: Trident Microsystems, Inc.

Specifications of PNX1301EH/G,557

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Philips Semiconductors
Signed sum of products of unsigned/signed
bytes
SYNTAX
FUNCTION
DESCRIPTION
bytes of rsrc1 and rsrc2; the four products are summed, and the result is written to rdest. The bytes from rsrc1 are
considered unsigned, but the bytes from rsrc2 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 rguard is 1, rdest is written; otherwise, rdest 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 rguard ] ifir8ui rsrc1 rsrc2 → rdest
if rguard then
rsrc1
rdest ← zero_ext8to32(rsrc1<31:24>) × sign_ext8to32(rsrc2<31:24>) +
ifir8ui
31
unsigned
zero_ext8to32(rsrc1<23:16>) × sign_ext8to32(rsrc2<23:16>) +
zero_ext8to32(rsrc1<15:8>) × sign_ext8to32(rsrc2<15:8>) +
zero_ext8to32(rsrc1<7:0>) × sign_ext8to32(rsrc2<7:0>)
Initial Values
23
operation optionally takes a guard, specified in rguard. If a guard is present, its LSB controls the
unsigned
ifir8ui
15
unsigned
rdest
operation computes four separate products of the four pairs of corresponding 8-bit
31
7
unsigned
ifir8ui r30 r70 → r90
IF r10 ifir8ui r30 r70 → r100
IF r20 ifir8ui r40 r80 → r110
ifir8ui r60 r50 → r120
0
signed
Operation
PRELIMINARY SPECIFICATION
rsrc2
31
signed
PNX1300/01/02/11 DSPCPU Operations
×
23
signed
0
×
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
ifir8ii ufir8uu ifir16
r90 ← 0xfa
no change, since guard is false
r110 ← 0x2bc0
r120 ← 0xfffe0200
+
15
signed
ATTRIBUTES
×
SEE ALSO
ufir16
Result
7
signed
×
ifir8ui
dspmul
2, 3
No
91
—
0
2
3
A-86