PNX1300 Philips, PNX1300 Datasheet - Page 328

• Manufacturer Part Number: PNX1300
• Description: Media Processors
• Manufacturer: Philips

Philips Semiconductors
Clipped signed subtract
SYNTAX
FUNCTION
DESCRIPTION
[2
modification of the destination register. If the LSB of rguard is 1, rdest is written; otherwise, rdest is not changed.
EXAMPLES
r30 = 0x1200, r40 = 0xff
r10 = 0, r30 = 0x1200, r40 = 0xff
r20 = 1, r30 = 0x1200, r40 = 0xff
r50 = 0x7fffffff, r90 = 0xffffffff
r70 = 0x80000000, r80 = 1
As shown below, the
The
31
[ IF rguard ] dspisub rsrc1 rsrc2
if rguard then {
}
rsrc1
–1..–2
temp
if temp < 0xfffffffff80000000 then
else if temp > 0x000000007fffffff then
else
dspisub
31
rdest
rdest
rdest
31
Initial Values
sign_ext32to64(rsrc1) – sign_ext32to64(rsrc2)
] (or [0x7fffffff..0x80000000]), and stores the clipped value into rdest. All values are signed integers.
0x80000000
0x7fffffff
temp<31:0>
operation optionally takes a guard, specified in rguard. If a guard is present, its LSB controls the
dspisub
Full-precision
33-bit result
signed
rdest
operation computes the difference rsrc1–rsrc2, clips the result into the 32-bit range
32
dspisub r30 r40
IF r10 dspisub r30 r40
IF r20 dspisub r30 r40
dspisub r50 r90
dspisub r70 r80
31
0
Clip to [2
rdest
Operation
signed
signed
31
–1..–2
PRELIMINARY SPECIFICATION
rsrc2
r60
r110
r120
31
31
]
PNX1300/01/02/11 DSPCPU Operations
r80
r100
0
0
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
r60
no change, since guard is false
r100
r110
r120
dspiabs dspiadd dspimul
dspuadd dspumul dspusub
signed
0x1101
0x1101
0x7fffffff
0x80000000
ATTRIBUTES
SEE ALSO
Result
dspisub
dspalu
1, 3
No
68
—
0
2
2
A-30