tm1300 NXP Semiconductors, tm1300 Datasheet - Page 315

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

Philips Semiconductors
Clipped signed subtract
SYNTAX
FUNCTION
DESCRIPTION
[2
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 = 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 r guard ] dspisub r src1 r src2
if r guard then {
}
r src1
–1..–2
temp
if temp < 0xfffffffff80000000 then
else if temp > 0x000000007fffffff then
else
dspisub
r dest
r dest
r dest
3
31
Initial Values
sign_ext32to64(r src1 ) – sign_ext32to64(r src2 )
] (or [0x7fffffff..0x80000000]), and stores the clipped value into r dest . All values are signed integers.
0x80000000
0x7fffffff
temp<31:0>
operation optionally takes a guard, specified in r guard . If a guard is present, its LSB controls the
dspisub
Full-precision
33-bit result
signed
r dest
operation computes the difference r src1 –r src2 , clips the result into the 32-bit range
3
dspisub r30 r40
IF r10 dspisub r30 r40
IF r20 dspisub r30 r40
dspisub r50 r90
dspisub r70 r80
3
0
Clip to [2
r dest
Operation
signed
signed
31
–1..–2
PRODUCT SPECIFICATION
r src2
r60
r110
r120
31
3
]
r80
r100
DSPCPU Operations for TM1300
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-29