CY7C68300 / CY7C68300A -- Maximum Capacity of Hard Drive that the EZ-USB AT2 can Support

Question: What is the maximum capacity of harddrive that the EZ-USB AT2 can handle?

 

Answer:

The AT2 was designed to the ATA/ATAPI-6 specification. It has 48 bit addressing so the maximum LBA would be 281,474,976,710,655 * 512 bytes/sector = 144e15 bytes or 144 peta bytes. The USB Mass Storage protocol uses ATAPI commands which only support up to 2^32-1 sectors, and so practically speaking the AT2 is limited to 2^41-512 bytes on a drive. That's 512 bytes less than 2.0 terabytes (2048 gigabytes).