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DES/3DES
S3C2501X
8-10
8.5 PERFORMANCE CALCULATION GUIDE
Supposed condition:
— DESINFIFO has already data to be encrypting.
— DESOUTFIFO can be written data to be encrypted.
Cycle Unit (Reference Figure 8-1 DES/3DES Block Diagram)
Unit 1: from DESINFIFO to input buffer (1+1/2 cycle)
Unit 2: from input buffer to DES engine (1 cycle)
Unit 3: DES operation (20 cycles for DES, 60 cycles for 3DES)
Unit 4: from DES engine to output buffer (1/2 cycle)
Unit 5: from output buffer to DESOUTFIFO (2 cycle)
total: 25 cycles for DES, 65 cycles for 3DES
Explain: DES engine consumes fixed cycle per block (25 cycles for DES, and 65 cycles for 3DES). If the DES
operating frequency is 133MHz and the DES has one block to be encrypted, the DES performance is
341 Mbps
for DES or
131 Mbps
for 3DES. For more real system condition, the user have to consider how many cycles is
needed for external memory access. The memory access cycle should be included the performance calculation
as follows
DES Performance Calculation Formula
P = (#num of block
×
64 bit) / {(time of one period)
×
[(#num of block
×
C
des
) + (C
mem2des
+ C
des2mem
)]}
— time of one period: 7.5 ns if operating frequency is 133 MHz
— C
des
: 25 for DES, 65 for 3DES
— C
mem2des
: the cycle from external memory to DESINFIFO
— C
des2mem
: the cycle from DESOUTFIFO to external memory
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 ...
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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 ...