Digi NS7520 manual Sram burst write

Models: NS7520

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T i m i n g D i a g r a m s

SRAM burst write

CS controlled, four word (4-2-2-2), burst write (wait = 2, BCYC = 01)

T1

TW

TW

T2

TW

T2

BCLK

 

 

 

 

 

 

 

 

30

30

 

TA* (Note-4)

 

 

 

 

 

TEA*/LAST (Note-4)

 

 

 

 

 

6

 

 

 

 

 

A[27:0]

 

 

 

 

 

36

 

 

 

 

 

BE[3:0]* (Note-2)

 

 

 

 

 

 

27

 

 

 

 

CS[4:0]*

 

 

 

 

 

 

9

 

 

 

 

write D[31:0]

 

 

 

 

 

 

29

 

 

 

 

Sync WE*

 

 

 

 

 

 

19

 

 

 

 

CS0WE*

 

 

 

 

 

12

 

 

 

 

 

RW*

 

 

 

 

 

Notes:

 

 

 

 

 

TW

T2

TW

T2

Note-1

T1

 

31

31

 

 

 

36

 

 

 

27

 

 

 

13

 

 

 

29

 

 

 

19

 

1If the next transfer is DMA, null periods between memory transfers can occur. Thirteen clock pulses are required for DMA context switching.

2Port size determines which byte enable signals are active:

8-bit port = BE3*

16-bit port = BE[3:0]

32-bit port = BE[3:0]

3The TW cycles are present when the WAIT field is set to 2 or more.

4The TA* and TEA*/LAST signals are for reference only.

2 7 6

N S 7 5 2 0 H a r d w a r e R e f e r e n c e , R e v . D 0 3 / 2 0 0 6

Page 290
Image 290
Digi NS7520 manual Sram burst write