Digi NS9750 User Manual

Page 828

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M e m o r y t i m i n g

8 0 4

N S 9 7 5 0 H a r d w a r e R e f e r e n c e

Table 468 describes the values shown in the SRAM timing diagrams (Figure 113
through Figure 118).

Notes:

1

The (CPU clock out / 2) signal is for reference only.

2

Only one of the four

dy_cs_n

signals is used. The diagrams show the active low configuration, which can be

reversed (active high) with the PC field.

3

Use this formula to calculate the length of the st_cs_n signal:

Tacc + board delay + (optional buffer delays, both address out and data in) + 10ns

Parm

Description

Min

Max

Unit

Notes

M15

clock high to data out valid

-2

+2

ns

M16

data out hold time from clock high

-2

+2

ns

M17

clock high to address valid

-2

+2

ns

M18

address hold time from clock high

-2

+2

ns

M19

clock high to st_cs_n low

-2

+2

ns

2

M20

clock high to st_cs_n high

-2

+2

ns

2

M21

clock high to we_n low

-2

+2

ns

M22

clock high to we_n high

-2

+2

ns

M23

clock high to byte_lanes low

-2

+2

ns

M24

clock high to byte_lanes high

-2

+2

ns

M25

data input setup time to rising clk

10

ns

M26

data input hold time to rising clk

0

ns

M27

clock high to oe_n low

-2

+2

ns

M28

clock high to oe_n high

-2

+2

ns

Table 468: SRAM timing parameters

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