What does an ATA-2 interface do?
Interfaces have come a long way since the ordinary ISA IDE consisting of little more than a simple buffer. ATA-2 boards have to support at least PIO modes 0 and 3, usually support many more modes, and will have to ensure that the correct timing is used at the ATA interface for each of these modes. Since the timing specifications are quite complicated, a great deal of flexibility is necessary to implement the ATA-2 standard correctly.
Interfaces have come a long way since the ordinary ISA IDE consisting of little more than a simple buffer. ATA-2 boards have to support at least PIO modes 0 and 3, usually support more, and will have to ensure that the correct timing is used at the ATA interface for each of these modes. Since the timing specifications are quite complicated, a great deal of flexibility is necessary to implement the ATA-2 standard correctly. The following figure defines the relationships between the interface signals for both 8-bit and 16-bit PIO data transfers. || __________________________________________ | Address Valid *1 _____/ \________ |||| | | |____________________________||_ DIOR-/DIOW- ____________/ \_____________/ | | | | | | ________|__ ->| |———— | | || | | | | ->|t4|—— ->|t7||t6 || tA ||| | |___________________________________________| IOCS16- ________/ | | \____ | ->|tRd|| *1 Device Address consists of signals CS0-, CS1- and DA2-0 *2 Data consists of DD0-15 (16-bit) or DD0-7 (8-
