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1 dma device address register (ddarn), 1dma device address register (ddarn) -8, Peripheral control module – Intel STRONGARM SA-1100 User Manual

Page 158

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11-8

SA-1100

Developer’s Manual

Peripheral Control Module

11.6.1.1

DMA Device Address Register (DDARn)

The DDARn is a 32-bit read/write register containing channel information regarding the target
device. Writes to this register are blocked if the RUN bit in the DCSRn is one. The following figure
shows the format for this register; question marks indicate that the values are unknown at reset.

.

1

“Partial” means that certain bits in the address are assumed to be zero. The DA<31:8> field is constructed as follows:

DA<31:28> = Device port address 31:28.

Device port address 27:22 is assumed to be zero.

DA<27:8> = Device port address 21:2.

Device port address 1:0 is assumed to be zero.

Bit

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

Read

DA

31

DA

30

DA

29

DA

28

DA

27

DA

26

DA

25

DA

24

DA

23

DA

22

DA

21

DA

20

DA

19

DA

18

DA

17

DA

16

Reset

0

0

0

0

?

?

?

?

?

?

?

?

?

?

?

?

-

Bit

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Read

DA

15

DA

14

DA

13

DA

12

DA

11

DA

10

DA

9

DA

8

DS

3

DS

2

DS

1

DS

0

DW

BS

E

RW

Reset

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

Bit

Name

Description

0

RW

Device data transfer direction (read/write).

0 = Transfer is a write (memory to device).

1 = Transfer is a read (device to memory).

1

E

Device endianess.

0 = Byte ordering is little endian.

1 = Byte ordering is big endian.

2

BS

Device burst size.

0 = Four datums per burst.

1 = Eight datums per burst.

3

DW

Device datum width.

0 = Datum size is one byte.

1 = Datum size is one half-word.

7..4

DS<3:0>

Device select.

This field is programmed to point to the desired device.

31..8

DA<31:8>

Device address field.

This field is a partial address of the data port of the device currently being serviced.

1