XCCACE128-I Xilinx Inc, XCCACE128-I Datasheet - Page 10

• Manufacturer Part Number: XCCACE128-I
• Description: IC 128MBIT ACE FLASH CARD
• Manufacturer: Xilinx Inc

Specifications of XCCACE128-I

• Memory Size: 128Mb
• Memory Type: FLASH
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

System ACE CompactFlash Solution
System ACE CF File Structure Requirements
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The System ACE CF file structure must be on the first
partition of the CompactFlash device.
The System ACE CF partition must be formatted as
DOS FAT12 or FAT16.
The xilinx.sys file or single ACE file must be in
the root directory. The ACE file used only if
xilinx.sys is not found. The xilinx.sys file
describes one collection directory with up to eight
subdirectories.
The xilinx.sys file must contain the line
dir=<dir_name>; where <dir_name> is the name of the
collection directory
The subsequent 8 lines of the xilinx.sys file must
consist of the lines cfgaddr<n>=<subdir_name>; where
<n> is 1 through 8 and <subdir_name> is the name of
a design sub-directory in the collection. In the case of
fewer than 8 designs in the collection, always start with
cfgaddr0 and only use contiguous cfgaddr locations.
Only one ACE file should exist in the ROOT directory
and/or in each \<dir>\<cfgaddr> folder pointed to
by the xilinx.sys file.
When sourcing from the MPU, the total length of the
ACE file must be a multiple of 32 bytes. Otherwise,
additional dummy bytes (1s or 0s) should be sent to
DATABUFREG to flush the last data buffer, allowing the
controller to correctly load the final commands in the
ACE file.
All directories accessed by the System ACE CF
controller must be formatted in a valid FAT 8.3 file
name format.
ACE file names can be up to eight characters long and
must include the .ace file extension.
All directories and ACE file names cannot contain
these reserved characters:
The Partition Boot Record (PBR) for the first
CompactFlash partition that is used by the System
ACE CF controller must specify only one reserved
sector.
The CompactFlash card must be formatted with a
sector-per-cluster size greater than 1.
Other files and directories can coexist with System
ACE files and directories.
2 GB is the maximum capacity partition that the
System ACE CF controller can access using the FAT16
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System ACE CF Formatting Requirements
Three potential problem areas arise when formatting the CF
card for use with the System ACE CF controller:
1. Sectors-per-Cluster Size
2. FAT12 or FAT16 Format
3. Reserved Sectors
Specifying Sectors-per-Cluster and FAT Version
To correct the first two of these formatting issues, the CF
card should always be formatted with a sectors-per-cluster
size greater than 1 (UnitSize greater than 512), and the FAT
file system version should be specified. This can be done
using the format command with the /fs: and /a:
options in this syntax:
For example:
file system:
(65,535 clusters max) X (32 KB per cluster max)
= 2,147,123,200 bytes → 2 GB
16 MB is the maximum capacity partition that the
System ACE CF controller can access using the FAT12
file system:
(4,086 clusters max) X (4 KB per cluster max)
= 16,736,256 bytes → 16 MB
A CF card formatted with only one sector (512 bytes)
per cluster can cause problems for the System ACE CF
controller.
When the Windows OS formats the CF card, it uses a
formula to determine what it believes to be an optimal
sectors-per-cluster value, based on the size of the CF
partition and other factors. This can lead some
Windows OS versions to specify one sector (512 bytes)
per cluster in some CF configurations. For example, this
situation is known to occur when formatting 32 MB CF
cards with Windows 2000 and Windows XP. Disk
formatting utilities (such as mkdosfs, available from
http://www1.mager.org/mkdosfs) can be used to
avoid this situation.
The System ACE CF controller does not recognize the
FAT32 file system. It was designed to recognize only the
FAT12 and FAT16 formats.
Reserved sectors are the sectors in the reserved region
of the volume starting at the first sector of the volume.
The System ACE CF controller can only read a CF card
that is formatted with one reserved sector in the
Partition Boot Record.
format <volume> [/fs:<FileSystem>]
[/a:<UnitSize>]
format D: /FS:FAT /A:1024
DS080 (v2.0) October 1, 2008
Product Specification
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