Registers

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4.2Asynchronous Wait Cycle Configuration Register (AWCCR)

The asynchronous wait cycle configuration register (AWCCR) is used to configure the parameters for extended wait cycles. Both the polarity of the EM_WAIT[5:2] pins and the maximum allowable number of extended wait cycles can be configured. the AWCCR is shown in Figure 21 and described in Table 34.

NOTE: The EW bit in the asynchronous configuration register (ACFGn) must be set to allow for the insertion of extended wait cycles.

Figure 21. Asynchronous Wait Cycle Configuration Register (AWCCR)

31

30

29

28

 

27

24

23

22

21

20

19

18

17

16

WP3

WP2

WP1

WP0

 

 

Reserved

CS5_WAIT

CS4_WAIT

CS3_WAIT

CS2_WAIT

R/W-1

R/W-1

R/W-1

R/W-1

 

R-0

R/W-3h

R/W-2h

 

R/W-1

R/W-0

 

15

 

 

 

 

 

8

7

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reserved

 

 

 

 

MEWC

 

 

 

 

 

 

R-0

 

 

 

 

 

R/W-80h

 

 

 

LEGEND: R/W = Read/Write; R = Read only; -n= value after reset

 

 

 

 

 

 

 

 

Table 34. Asynchronous Wait Cycle Configuration Register (AWCCR) Field Descriptions

Bit

 

Field

Value

Description

 

 

 

 

 

 

 

31

 

WP3

 

WAIT polarity bit. This bit defines the polarity of the EM_WAIT[5] pin.

 

 

 

 

0

Insert wait cycles if EM_WAIT[5] pin is low.

 

 

 

 

1

Insert wait cycles if EM_WAIT[5] pin is high.

 

 

 

 

 

 

 

30

 

WP2

 

WAIT polarity bit. This bit defines the polarity of the EM_WAIT[4] pin.

 

 

 

 

0

Insert wait cycles if EM_WAIT[4] pin is low.

 

 

 

 

1

Insert wait cycles if EM_WAIT[4] pin is high.

 

 

 

 

 

 

 

29

 

WP1

 

WAIT polarity bit. This bit defines the polarity of the EM_WAIT[3] pin.

 

 

 

 

0

Insert wait cycles if EM_WAIT[3] pin is low.

 

 

 

 

1

Insert wait cycles if EM_WAIT[3] pin is high.

 

 

 

 

 

 

 

28

 

WP0

 

WAIT polarity bit. This bit defines the polarity of the EM_WAIT[2] pin.

 

 

 

 

0

Insert wait cycles if EM_WAIT[2] pin is low.

 

 

 

 

1

Insert wait cycles if EM_WAIT[2] pin is high.

 

 

 

 

 

 

 

27-24

 

Reserved

0

Reserved

 

 

 

 

 

 

23-22

 

CS5_WAIT

0-3h

EM_WAIT[5:2] pin map for chip select 5. By default, the EM_WAIT[5] pin is used for chip select 5.

 

 

 

0

EM_WAIT[2] pin is used.

 

 

 

 

1h

EM_WAIT[3] pin is used.

 

 

 

 

2h

EM_WAIT[4] pin is used.

 

 

 

 

3h

EM_WAIT[5] pin is used.

 

 

 

 

 

 

21-20

 

CS4_WAIT

0-3h

EM_WAIT[5:2] pin map for chip select 4. By default, the EM_WAIT[4] pin is used for chip select 4.

 

 

 

0

EM_WAIT[2] pin is used.

 

 

 

 

1h

EM_WAIT[3] pin is used.

 

 

 

 

2h

EM_WAIT[4] pin is used.

 

 

 

 

3h

EM_WAIT[5] pin is used.

 

 

 

 

 

 

19-18

 

CS3_WAIT

0-3h

EM_WAIT[5:2] pin map for chip select 3. By default, the EM_WAIT[3] pin is used for chip select 3.

 

 

 

0

EM_WAIT[2] pin is used.

 

 

 

 

1h

EM_WAIT[3] pin is used.

 

 

 

 

2h

EM_WAIT[4] pin is used.

 

 

 

 

3h

EM_WAIT[5] pin is used.

 

 

 

 

 

 

 

 

 

 

 

 

 

50

Asynchronous External Memory Interface (EMIF)

SPRUEQ7C –February 2010

 

 

 

 

 

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Texas Instruments TMS320DM646X DMSOC manual Asynchronous Wait Cycle Configuration Register Awccr, WP3 WP2 WP1 WP0, CS5WAIT