PNX1300 Datasheet, PDF (449/548 Pages) NXP Semiconductors – Media Processors

PNX1300/01/02/11 Data Book
quadumin
Philips Semiconductors
Unsigned bytewise quad minimum
SYNTAX
[ IF rguard ] quadumin rsrc1 rsrc2 → rdest
FUNCTION
if rguard then {
rdest<7:0> ← if rsrc1<7:0> < rsrc2<7:0> then rsrc1<7:0> else rsrc2<7:0>
rdest<15:8> ← if rsrc1<15:8> < rsrc2<15:8> then rsrc1<15:8> else rsrc2<15:8>
rdest<23:16> ← if rsrc1<23:16> < rsrc2<23:16> then rsrc1<23:16> else rsrc2<23:16>
rdest<31:24> ← if rsrc1<31:24> < rsrc2<31:24> then rsrc1<31:24> else rsrc2<31:24>
}
ATTRIBUTES
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
dspalu
80
2
No
—
2
1,3
SEE ALSO
imin imax quadumax
DESCRIPTION
The quadumin operation computes four separate minimum values of the four pairs of corresponding 8-bit bytes of
rsrc1 and rsrc2. All bytes are considered unsigned. The quadumin operation is particularly suited to implement
median computation on packed pixel data structures:
MEDIAN_Q(a,b,c) (QUADUMIN(QUADUMAX( QUADUMIN((a),(b)), (c)), QUADUMAX((a),(b))))
The quadumin operation optionally takes a guard, specified in rguard. If a guard is present, its LSB controls the
modification of the destination register. If the LSB of rguard is 1, rdest is written; otherwise, rdest is not changed.
EXAMPLES
Initial Values
Operation
r30 = 0x0201000e, r40 = 0xff00ff02
quadumin r30 r40 → r50
r10 = 0, r60 = 0x9c9c6464, r70 = 0x649d649c IF r10 quadumin r60 r70 → r80
r20 = 1, r60 = 0x9c9c6464, r70 = 0x649d649c IF r20 quadumin r60 r70 → r90
Result
r50 ← 0x02000002
no change, since guard is false
r90 ← 0x649c6464
A-151
PRELIMINARYSPECIFICATION