TMS320C66x 3- . . . ; . , , . , . L1. L2 , . . ( ) -.
TMS320C66xx :
- L1P L1D, ;
- L2 ;
- MSM (Multicore Shared Memory), L2 L3;
- L3.
L1 L2 , -, L2 L3. , . TMS320C66x.
1 — CorePac TMS320C66xx
CorePac TMS320C66x. , 1. – 66, – , :
- L1 (L1P);
- L1 (L1D);
- L2 (L2);
- (IDMA)
- (EMC);
- (XMC);
.
-
, TMS320C66x, .
. , , L1, . L2 , , , . L3, L4 , , . .
– (temporal and spatial locality) [1]. . , / . / /, , , / .
/, , (cache line). , , , /, , , /. L1P 32 . , , , TMS320C66x L1P .
(direct-mapped cache). , . , , . /, , . (conflict miss), . – - (capacity miss). – (compulsory miss). .
, . , ( – 2 way), 4 ( – 4-way) . , / / , ( — way) . , . , , (Set). , , , . LRU, . .
| way1 | way2 | |
|---|---|---|
| set1 | line0 | line0 |
| set2 | line1 | line1 |
| set3 | line2 | line2 |
« » (read-allocate cache) – , , / , . ( , ) (write buffer) .
/ (write back cache) , (write hit) / , , (Dirty), .
TMS320C66xx . L2 L1, L1, . , , . L1P . 16 , MAR.
, , MEMORY cmd-.
(cache coherence). () . , , . , , , , .
C66x EDMA/IDMA. DMA L2 SRAM, L1D- L2 SRAM. DMA L2 SRAM, L2 SRAM, L1D. snooping – . DMA / .
( CSL) :
- DMA , CPU;
- CPU , DMA ;
- DMA L2 SRAM, CPU;
- L2 SRAM , .
. C 1 DMA L2 . DMA L2 2. , , ping-pong . L2 L1 .
2 ping-pong 2 – L2 L1 – . DMA L1D L2, , (invalidate). , . , , DMA , L1D L2 – write back.
- . . Texas Instruments Code Composer Studio . .
L1P
L1 (L1P) . TMS320C6678 32 . L1P . 0, 4, 8, 16 32 . . L1P. L1P , ( ).
L1P . L1P EDMA IDMA. L1P , - .
L1P 0, , L1P 3. L1P . .
L1P . L1P (direct-mapped cache). . , , , .
L1P (freeze mode) . , . L1P . - , «» .
L1P . , , . (invalidation) . , .
, , .
. . . , , , , .
L1P- , ( ). . L1P- L2- . , , . - ( ) - . TMS320C66x , - , . , , , . – , . , L2 , L1P. (L1P miss pipeline).
66 .
, , , , , . - .
, . L1P (static power-down), ; , «» L1P IDLE. (dynamic power-down), SPLOOP. L1P- (feature-oriented power-down), (disabled). L1P , , .
L1P , DMA IDMA. 2 – . . , ( ) ( DMA/IDMA). , L1P L1P .
/ DMA/IDMA . . L1P 16 .
L1D
L1 128 TMS320C6678 32 . L1D -.
L1D- – « » « » (2-way set-associative, read-allocate, write back cache). .
L1D . L1D .
. 32- , , , .
2 —
offset – . , , . 64 offset 6 . .
set – , . set - 5-14 .
Tag , , (way).
- , , . (write back) , . L1D- .
L1D . LRU . . . . , L1D L1P. .
L1D- :
- (invalidation);
- (writeback);
- (writeback-invalidation).
, L1P. L1P L1D ( ), writeback-invalidate, L2-.
L1D- L2, DMA, L1D- , L2. L2 / (snoop-read snoop-write) DMA. snoop-read L2, L2 , DMA (Dirty). L1D L2. snoop-write , L2 , , DMA, L1D-. L1D , .
L1D L2 , L2 () L1D-. L1D L2 , L2 , L1D . L2 , L1D , L1D.
L1D. 8 . – 4 . – , . . , , ; . DMA, – . , , . L1D .
L1D . , , . L1D L2, L2, — L3. 2 , , . , , .
(victim buffer). , , , . , , , . , . . . , L2, (L1D write buffer).
L1D , (L2) . (write buffer). 128 4-, 4 L2 . , . . , , . , , , , .
L2 , , L1. . , . , , . , , 128 , L2 ( ) . . L2. .
, L1P, .
L1D- L1P. L1D , (idle mode). IDLE , ( ) . , L1D, L1P L2 DMA (PDC) «» , DMA . . .
L1D L1D / , . , . ( , DSP IDMA) . . , , , , . .
L2
L2 64 — 4096 TMS320C6678 512 . L2 1 256 . L2 , 4 . 128- . L2 L1D, L1P IDMA .
L2 . .
L2- 4- -. L1 L2- - , . 3 — (offset), (set) (tag). . L2- 128-, 7 . Set . Tag , (Way) , , .
L1. L2- . L1- L2 - , L2- . DSP. XMC.
L2 . , , .
L2- « » . -. CorePac .
, L1.
L2. L1, . L1-.
, . (MAR). . , . , . MAR . , [2].
L1P L1D L2, L2 ( ), L2 MAR- . , « » – L2 L1D ( ). DSP , . L1P , , MAR-.
L1 L2. L2 L1D-. L2 L1P, ( ) - L2 L1.
L1 L2 – snoop-. Snoop-read – – L2, DMA L2 , L1D , L1 L2 , . L2 L1D- , ( , LRU ). Snoop-write – – L2 L2 DMA , L1D-. , , . 256 L2 L1D. .
L2- «» , L1D ( L1P) .
L1 L3 ( L2 ) – victim writebacks – L2 , L2-, , L2-.
XMC L2- MAR.
L2 . – . – , ( CorePac) . . DMA L1PD L2, , DMA (PDC) .
L2 . L2 Retenion Until Access – RTA. «» , . , L2 , .
L2, L1, , . . [2].
— IDMA
DMA – IDMA – , L1P, L1D L2, (CFG). 2 . – L1 L2-. IDMA L1 L2- , . – IDMA CFG-. IDMA .
IDMA 2 . 0 (channel 0) – CFG. 1 (channel 1) . IDMA DMA- DSP- . [2].
— EMC
EMC CorePac . , , .
EMC 2 – CFG DMA «» — Slave DMA – SDMA. SDMA , , DMA ( ), SRIO , . , , .
— XMC
XMC 4 :
- MSMC – MDMA- L2- MSM-;
- , CorePac;
- ;
- (prefetching).
CorePac MSM.
( ) MSM RAM EMIF CorePac.
MPAX. , .
TMS320C66x 32- . 4 . , . , 32- CorePac 36-. 36- 64 .
32- 16 , , , MSM. .
XMC . MPAX, XMC .
MPAX . 16 MPAX 3.
3 — MPAX
BADDR SEGSZ . 4 4 . . 36- , , , ( ) . , , .
[2]. , , , , .
:
:
- TMS320C66x DSP Cache. User Guide. SPRUGY8. Texas Instruments, 2010
- TMS320C66x DSP CorePac. User Guide. SPRUGW0B. USA. Texas Instruments, 2011