tm1300 NXP Semiconductors, tm1300 Datasheet - Page 429

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

Philips Semiconductors
prefetch
pseudo-op for prefd(0)
SYNTAX
[ IF r guard ] pref r src1
FUNCTION
DESCRIPTION
(Note: pseudo operations cannot be used in assembly files.)
cache_block_mask) and stores the data into the data cache. This operation is not guaranteed to be executed. The
prefetch unit will not execute this operation when the data to be prefetched is already in the data cache. A pref
operation will not be executed when the cache is already occupied with 2 cache misses, when the operation is issued.
of the prefetch operation. If the LSB of rguard is 1, prefetch operation is executed; otherwise, it is not executed.
NOTE: This operation is supported only in TM1000, TM1100 and TM1300 and it is not
guaranteed to be available in future generations of Trimedia products.
r10 = 0xabcd,
cache_block_size = 0x40
r10 = 0xabcd, r11 = 0,
cache_block_size = 0x40
r10 = 0xabff, r11 = 1,
cache_block_size = 0x40
The pref operation is a pseudo operation transformed by the scheduler into an prefd(0) with the same arguments.
The pref operation loads the one full cache block size of memory value from the address computed by ((rsrc1+0) &
The pref operation optionally takes a guard, specified in rguard. If a guard is present, its LSB controls the execution
EXAMPLES
if r guard then {
}
cache_block_mask = ~(cache_block_size - 1)
data_cache <- mem[(rsrc1 + 0) & cache_block_mask]
Initial Values
pref r10
IF r11 pref r10
IF r11 pref r10
Operation
PRODUCT SPECIFICATION
Loads a cache line for the address space from
0xabc0 to 0x0xabff from the main memory. If the data
is already in the cache, the operation is not executed.
since guard is false, pref operation is not executed
Loads a cache line for the address space from
0xabc0 to 0x0xabff from the main memory. If the data
is already in the cache, the operation is not executed.
DSPCPU Operations for TM1300
prefr allocd allocr allocx
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
pref16x pref32x prefd
Result
ATTRIBUTES
SEE ALSO
dmemspec
209
pref
1
5
-
-
-
A-143