Digi NS9750 User Manual

Page 178

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S t a t i c m e m o r y c o n t r o l l e r

1 5 4

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

Byte lane control and databus steering

For little and big endian configurations, address right-justified

The tables in this section (Table 79 through Table 125) show the relationship of
signals

HSIZE[2:0]

,

HADDR[1:0]

,

ADDROUT[1:0]

, and

BLSOUT[3:0]

and mapping of data

between the AHB system databus and the external memory databus. This mapping
applies to both the static and dynamic memory controllers.

Access: Read, little endian, 8-bit external
bus

External data mapping on to system
databus

Internal
transfer
width

HRDATA to DATA

HSIZE
[2:0]

HADDR
[1:0]

ADDROUT
[1:0]

BLSOU
T [0]

[31:24]

23:16]

[15:8]

[7:0]

Word (4
transfers)

010

--

11

10

01

00

0

0

0

0

[7:0]

-

-

-

-

[7:0]

-

-

-

-

[7:0]

-

-

-

-

[7:0]

Halfword (2
transfers)

001

1-

11

10

0

0

[7:0]

-

-

[7:0]

-

-

-

-

Halfword (2
transfers)

001

0-

01

00

0

0

-

-

-

-

[7:0]

-

-

[7:0]

Byte

000

11

11

0

[7:0]

-

-

-

Byte

000

10

10

0

-

[7:0]

-

-

Byte

000

01

01

0

-

-

[7:0]

-

Byte

000

00

00

0

-

-

-

[7:0]

Table 79: Little endian read, 8-bit external bus

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