CompactFlash Association announces revision 3.0 of the CF+ & CompactFlash specification

The CF+ & CompactFlash Specification Revision 3.0 increases the CompactFlash interface data transfer rate from 16MB/sec to 66MB/sec, while maintaining forward and backward compatibility with old and new host systems.

Flash chip and controller technology advances have allowed flash chips to achieve sustained data transfer rates of over 12MB/sec. The development of the 66MB/sec interface means that the CompactFlash interface will not restrict the sustained data transfer rate of CompactFlash cards in the near future.

DMA interface mode is also included and reduces the processor power required to manage the CompactFlash data transfers. Ultra DMA 33 and UltraDMA66 interface modes will increase the CompactFlash interface data transfer rate to 66MB/sec. Both of these DMA interface modes are well defined and tested by their usage on IDE hard disk drives.

Faster PCMCIA ATA Memory and I/O modes have also been added and can provide interface transfer rates up to 25MB/sec.

The original and current CompactFlash Specification allows for addressing 137GB cards. However, there is another issue that limits the usable size of CompactFlash cards. Currently the FAT16 file system is used for cards up to 2.2GB. To use the full capacity of cards over 2.2GB capacity, the FAT32 file system is necessary.

The CFA is currently recommending that systems be designed to be compatible with FAT12, FAT16 and FAT32 file systems in order to be able to use the full capacity range of CompactFlash cards currently being offered. The newest digital cameras now support FAT12, FAT16 and FAT32.