M e m o r y C o n t r o l l e r M o d u l e

Chip Select Option Register B

Address: FFC0 0018/28/38/48/58

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reserved

 

 

 

 

WAIT[5:4]

BCYC[3:2]

 

SYNC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

Access

Mnemonic

Reset

Description

 

 

 

 

 

D31:06

N/A

Reserved

N/A

N/A

 

 

 

 

 

D05:04

R/W

WAIT[5:4]

0 for

Memory timing control fields

 

 

 

CS[4:1],

The WAIT field controls the number of

 

 

 

’b11 for

wait states for all single cycle memory

 

 

 

CS0

transfers and the first memory cycle of a

 

 

 

 

burst transaction. The complete WAIT

D03:02

R/W

BCYC[3:2]

0

field is the concatenation of the four

 

 

 

 

WAIT bits in Chip Select Option Register A and the two WAIT bits in this register.

The BCYC field controls the number of clock cycles for the secondary portion of a burst cycle. The complete BCYC field is the concatenation of the two BCYC bits in Chip Select Option Register A and the two BCYC bits in this register.

For OE- or WE-controlled cycles, an additional BCLK cycle is added to each memory cycle.

For information about related DRSEL and DMODE settings, see the Chip Select Option Register A bit definition table (on page 97).

Table 39: Chip Select Option Register B bit definition

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Page 115
Image 115
Digi NS7520 manual Chip Select Option Register B bit definition