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S3C2501X
SYSTEM CONFIGURATION
4-7
4.6.1 PROBLEM SOLVINGS WITH PROGRAMMABLE ROUND-ROBIN
S3C2501X has a stuff to think about with arbiter operation. This only applies to arbiter with Round-Robin priority.
Assuming all '0's are set for HPRIR register for Round-Robin, HPRIR (all same bus occupancy in Round-Robin),
and only three of six masters are used, the problem arises as follows.
Number
HPRIR
Channel
Expected Bus
Occupancy
Actual Running
Block
Real System
Bus Occupancy
1
0
GDMA
1/3
GDMA
1/6
2
0
Ethernet Controller 0
1/3
Ethernet Controller 0
1/6
3
0
Ethernet Controller 1
1/3
Ethernet Controller 1
1/6
4
0
Reserved Master 0
0
GDMA
1/6
5
0
Reserved Master 1
0
GDMA
1/6
6
0
Reserved Master 2
0
GDMA
1/6
When HPRIR is 0x0 and only GDMA , Ethernet controller 0 and 1 are used, the expected bus occupancy for each
channel is 1/3. However, S3C2501X does not work that way, instead, GDMA gets 4/6 of the bus occupancy,
Ethernet controller 0 1/6, and Ethernet controller 1 1/6. In short, GDMA is run four times more than Ethernet
controller 0 and 1. This is because S3C2501X is designed to turn the bus occupancy to the next master when
there is non-used master. For instance,
Number 1: GDMA
Number 2: Ethernet controller 0
Number 3: Ethernet controller 1
Number 4: Reserved Master 0
→
go to number 5: Reserved Master 1
→
go to number 6: Reserved Master 2
→
go to number 1: GDMA
Number 5: Reserved Master 1
→
go to number 6: Reserved Master 2
→
go to number 1: GDMA
Number 6: Reserved Master 2
→
go to number 1: GDMA
Содержание S3C2501X
Страница 1: ...S3C2501X 32 BIT RISC MICROPROCESSOR USER S MANUAL Revision 1 查询S3C2501X供应商 捷多邦 专业PCB打样工厂 24小时加急出货 ...
Страница 18: ......
Страница 275: ...MEMORY CONTROLLER S3C2501X 5 60 NOTES ...
Страница 289: ...I2C CONTROLLER S3C2501X 6 14 NOTES ...
Страница 373: ...GDMA CONTROLLER S3C2501X 9 24 NOTES ...
Страница 435: ...I O PORTS S3C2501X 12 12 NOTES ...
Страница 463: ...ELECTRICAL DATA S3C2501X 15 6 NOTES ...