tm1300 NXP Semiconductors, tm1300 Datasheet - Page 433

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

Philips Semiconductors
prefetch with index
SYNTAX
[ IF r guard ] prefr r src1 r src2
FUNCTION
DESCRIPTION
((rsrc1+rscr2) & 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 prefr operation will not be executed when the cache is already occupied with 2 cache misses, when the operation is
issued.
execution of the prefetch operation. If the LSB of r guard is 1, prefetch operation is executed; otherwise, it is not
executed..
EXAMPLES
NOTE: This operation is supported only in TM1000, TM1100 and TM1300 and it is not
guaranteed to be available in future generations of this product.
r10 = 0xabcd, r12 = 0xd
cache_block_size = 0x40
r10 = 0xabcd, r11 = 0, r12=0xd,
cache_block_size = 0x40
r10 = 0xabff, r11 = 1, r12 =0x1,
cache_block_size = 0x40
The prefr operation loads the one full cache block size of memory value from the address computed by
The
i f r guard then {
}
cache_block_mask = ~(cache_block_size - 1)
data_cache <- mem[(rsrc1 + rscr2) & cache_block_mask]
prefr
Initial Values
operation optionally takes a guard, specified in r guard . If a guard is present, its LSB controls the
prefr r10 r12
IF r11 prefr r10 r12
IF r11 prefr r10 r12
Operation
PRODUCT SPECIFICATION
Loads a cache line for the address space from
0xabc0 to 0x0xac3f from the main memory. If the
data is already in the cache, the operation is not exe-
cuted.
since guard is false, prefr operation is not executed
Loads a cache line for the address space from
0xac00 to 0x0xac3f from the main memory. If the
data is already in the cache, the operation is not exe-
cuted.
DSPCPU Operations for TM1300
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
pref16x pref32x prefd
allocd allocr allocx
Result
ATTRIBUTES
SEE ALSO
dmemspec
prefr
210
No
2
5
-
-
A-147