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Intel PXA255 User Manual

Page 217

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Intel® PXA255 Processor Developer’s Manual

6-35

Memory Controller

11:10

SXCA0

SX Memory column address bit count for partition pair 0/1

00 – 7 column address bits

01 – 8 column address bits

10 – 9 column address bits

11 – 10 column address bits

9:8

SXRA0

SX Memory row address bit count for partition pair 0/1

00 – 12 row address bits

01 – 13 row address bits

10 – reserved

11 – reserved

7:5

SXRL0

RAS Latency for Synchronous Static (SX) Memory partition pair 0/1

Number of external SDCLK cycles between reception of the ACT command and reception
of the READ command. The unit size for SXRL0 is the external SDCLK cycle.

IF SXTP0 = 00 (SMROM):

000 – 1 clock

001 – 2 clocks

010 – 3 clocks

011 – 4 clocks

100 – 5 clocks

101 – 6 clocks

110 – 7 clocks

111 – 8 clocks

IF SXTP0 = 10 (non-SDRAM timing Fast Flash), this field is not used and must be
programmed to 111

Table 6-13. SXCNFG Bit Definitions (Sheet 3 of 4)

0x4800_001C

SXCNFG

Memory Controller

Bit

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

reser

ved

S

X

LA

TC

H

2

SXTP

2

SX

C

A

2

SX

R

A

2

SXRL2

SXCL2

S

XEN

2

reser

ved

S

X

LA

TC

H

0

SXTP

0

SX

C

A

0

SX

R

A

0

SXRL0

SXCL0

S

XEN

0

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

*

*

*

*

*

*

*

*

*

*

*

*

*

0

*

Bits

Name

Description