
Philips Semiconductors
DSPCPU Operations for TM1300
PRODUCT SPECIFICATION
A-103
Signed 16-bit load
pseudo-op for ild16d(0)
SYNTAX
[ IF rguard ] ild16 rsrc1
→
rdest
FUNCTION
if
rguard
then {
if
PCSW.bytesex = LITTLE_ENDIAN
then
bs
←
1
else
bs
←
0
temp<7:0>
←
mem[(rsrc1+(1
⊕
bs)]
temp<15:8>
←
mem[(rsrc1+ (0
⊕
bs)]
rdest
←
sign_ext16to32(temp<15:0>)
}
ATTRIBUTES
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
dmem
6
1
No
—
3
4, 5
DESCRIPTION
The
ild16
operation is a pseudo operation transformed by the scheduler into an
ild16d(0)
with the same
argument. (Note: pseudo operations cannot be used in assembly source files.)
The
ild16
operation loads the 16-bit memory value from the address contained in rsrc1 sign extends it to 32 bits,
and stores the result in rdest If the memory address contained in rsrc1 is not a multiple of 2, the result of
ild16
is
undefined but no exception will be raised. This load operation is performed as little-endian or big-endian depending on
the current setting of the bytesex bit in the PCSW.
The result of an access by
ild16
to the MMIO address aperture is undefined; access to the MMIO aperture is
defined only for 32-bit loads and stores.
The
ild16
operation optionally takes a guard, specified in rguard If a guard is present, its LSB controls the
modification of the destination register and the occurrence of side effects. If the LSB of rguardis 1, rdestis written and
the data cache status bits are updated if the addressed locations are cacheable. if the LSB of rguard is 0, rdest is not
changed and
ild16
has no side effects whatever.
EXAMPLES
Initial Values
Operation
Result
r10 = 0xd00, [0xd00] = 0x22,
[0xd01] = 0x11
r30 = 0, r20 = 0xd04, [0xd04] = 0x84,
[0xd05] = 0x33
r40 = 1, r20 = 0xd04, [0xd04] = 0x84,
[0xd05] = 0x33
r50 = 0xd01
ild16 r10
→
r60
r60
←
0x00002211
IF r30 ild16 r20
→
r70
no change, since guard is false
IF r40 ild16 r20
→
r80
r80
←
0xffff8433
ild16 r50
→
r90
r90 undefined, since 0xd01 is not a multiple of 2
SEE ALSO
ild16d ild16r ild16x
ild16