Digi NS9215 manual S D M a b u f f e r d e s c r i p t o r, Block diagram, Data blocks

A E S D A T A E N C R Y P T I O N / D E C R Y P T I O N M O D U L E

AES DMA buffer descriptor

Block diagram

From System Memory

Ch 1 Ext DMA

Source

	Mode and Control
	IV
	Expanded Key
Key
Expander	Data In
FIFO

AES

Engine

Data Out

To System Memory

Ch 1 Ext DMA

Destination

FIFO

Data blocks	The AES module works on 128-bit blocks of data. This table shows the performance
	per each 128-bit block, depending on the key size:
			Key size
	Characteristic	128	192	256
	Number of cycles	44	52	60
	Latency (cycles)	44	52	60
	Throughput (bits/cycles)	~2.90	~2.46	~2.13
	Throughput @ 75 MHz (bytes/sec)	~27.19	~23.06	~19.97

A E S D M A b u f f e r d e s c r i p t o r

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The AES DMA buffer descriptor is the same as the external DMA buffer descriptor, with the exception of the control bits — AES op and AES control.

356Hardware Reference NS9215