Cirrus Logic EP93xx User Manual

Page 521

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DS785UM1

13-25

Copyright 2007 Cirrus Logic

SDRAM, SyncROM, and SyncFLASH Controller

EP93xx User’s Guide

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The value written to this bit specifies a synchronous
memory page size of 2 KBytes, or not:

0 - Page size is not 2 KByte
1 - Page size is 2 KByte

Only one of the SROM512, SROMLL, and 2KPAGE bits
can be ‘1’ at any time. With the exception of SROMLL,
these bits always operate in 32-bit memory bus width
mode regardless of the setting of External Bus Width bit.

SROMLL:

SROM Look-a-Like - Read/Write

The value written to this bit specifies if a SyncFLASH
device is operated in a manner that mimics a SycnROM
device, or not:

0 - SyncFLASH device does not mimic SycnROM device
1 - SyncFLASH device mimics SycnROM device (16-bit
wide memory bus only as specified by External Bus Width
= ‘0’)

If this bit is written to ‘1’, the signals on the BA0 and BA1
pins are exchanged with the signals on the AD12 and
AD13 pins, respectively.

Only one of the SROM512, SROMLL, and 2KPAGE bits
can be ‘1’ at any time. With the exception of SROMLL,
these bits always operate in 32-bit memory bus width
mode regardless of the setting of External Bus Width bit.

SROM512:

Synchronous ROM 512 byte page - Read/Write

The value written to this bit specifies if a SyncROM device
has a page size of 512 bytes, or not:

0 - Page size is not 512 bytes
1 - Page size is 512 bytes

Only one of the SROM512, SROMLL, and 2KPAGE bits
can be ‘1’ at any time. With the exception of SROMLL,
these bits always operate in 32-bit memory bus width
mode regardless of the setting of External Bus Width bit.

BankCount:

Bank Count - Read/Write

The value written to this bit specifies the number of banks
that are inside an SDRAM device:

1 - Four banks
0 - Two banks

External Bus Width:External Bus Width - Read/Write

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