Xilinx SP605 manual System ACE CF and CompactFlash Connector

Chapter 1: SP605 Evaluation Board

FPGA Design Considerations for the Configuration Flash

The SP605 has the P30 BPI flash connected to the FPGA dual use configuration pins and is not shared. It can be used to configure the FPGA, and then controlled post-configuration via the FPGA fabric. After FPGA configuration, the FPGA design can disable the configuration flash or access the configuration flash to read/write code or data.

When the FPGA design does not use the configuration flash, the FPGA design must drive the FLASH_OE_B pin High in order to disable the configuration flash and put the flash into a quiescent, low-power state. Otherwise, the flash memory can continue to drive its array data onto the data bus causing unnecessary switching noise and power consumption.

For FPGA designs that access the flash for reading/writing stored code or data, connect the FPGA design or EDK embedded memory controller (EMC) peripheral to the flash through the pins defined in Figure 1-7, page 18.

References

See the Numonyx StrataFlash Embedded Memory Data Sheet for more information. [Ref 14]

In addition, see the Spartan-6 FPGA Configuration User Guide for more information. [Ref 2]

5. System ACE CF and CompactFlash Connector

The Xilinx System ACE CompactFlash (CF) configuration controller allows a Type I or Type II CompactFlash card to program the FPGA through the JTAG port. Both hardware and software data can be downloaded through the JTAG port. The System ACE CF controller supports up to eight configuration images on a single CompactFlash card. The configuration address switches allow the user to choose which of the eight configuration images to use.

The CompactFlash (CF) card shipped with the board is correctly formatted to enable the System ACE CF controller to access the data stored in the card. The System ACE CF controller requires a FAT16 file system, with only one reserved sector permitted, and a sector-per-cluster size of more than one (UnitSize greater than 512). The FAT16 file system supports partitions of up to 2 GB. If multiple partitions are used, the System ACE CF directory structure must reside in the first partition on the CompactFlash, with the xilinx.sys file located in the root directory. The xilinx.sys file is used by the System ACE CF controller to define the project directory structure, which consists of one main folder containing eight sub-folders used to store the eight ACE files containing the configuration images. Only one ACE file should exist within each sub-folder. All folder names must be compliant to the DOS 8.3 short file name format. This means that the folder names can be up to eight characters long, and cannot contain the following reserved characters: < > " / \ . This DOS 8.3 file name restriction does not apply to the actual ACE file names.

Other folders and files may also coexist with the System ACE CF project within the FAT16 partition. However, the root directory must not contain more than a total of 16 folder and/or file entries, including deleted entries. When ejecting or unplugging the CompactFlash device, it is important to safely stop any read or write access to the CompactFlash device to avoid data corruption.

20	www.xilinx.com	SP605 Hardware User Guide
		UG526 (v1.1.1) February 1, 2010