tm1300 NXP Semiconductors, tm1300 Datasheet - Page 363

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

Philips Semiconductors
Signed select byte
SYNTAX
FUNCTION
DESCRIPTION
bits, and stores the result in r dest . The value of r src2 determines which byte is selected, with r src2 =0 selecting the
LSB of r src1 and r src2 =3 selecting the MSB of r src1 . If rsrc2 is not between 0 and 3 inclusive, the result of
is undefined.
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 = 0x44332211, r40 = 1
r10 = 0, r60 = 0xddccbbaa, r70 = 2
r20 = 1, r60 = 0xddccbbaa, r70 = 2
r100 = 0xffffff7f, r110 = 0
As shown below, the
The
[ IF r guard ] ibytesel r src1 r src2
if r guard then {
}
r src1
if r src2 = 0 then
else if r src2 = 1 then
else if r src2 = 2 then
else if r src2 = 3 then
ibytesel
r dest
r dest
r dest
r dest
3
signed
Initial Values
sign_ext8to32(r src1 <7:0>)
sign_ext8to32(r src1 <15:8>)
sign_ext8to32(r src1 <23:16>)
sign_ext8to32(r src1 <31:24>)
2
operation optionally takes a guard, specified in r guard . If a guard is present, its LSB controls the
3
signed
ibytesel
2
1
1
r dest
signed
operation selects one byte from the argument, r src1 , sign-extends the byte to 32
ibytesel r30 r40
IF r10 ibytesel r60 r70
IF r20 ibytesel r60 r70
ibytesel r100 r110
S
3
0
S
S
7
S
S
signed
S
S
S
S
S
0
S
S
Operation
r dest
S
S
S
S
S
S
PRODUCT SPECIFICATION
r src2
S
r50
S
S
r120
3
S
S
S
7
S
7
S
r80
r90
signed
signed
DSPCPU Operations for TM1300
r50
no change, since guard is false
r90
r120
0
0
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
ubytesel sex8 packbytes
0x00000022
0xffffffcc
0x0000007f
ATTRIBUTES
SEE ALSO
Result
ibytesel
ibytesel
1, 2, 3, 4, 5
1
alu
No
56
—
0
2
1
A-77