Advanced Technology Attachment (ATA) is the standard interface for connecting storage devices such as hard disks and CD-ROM/DVD drives inside personal computers. With the introduction of Serial ATA in 2003 the original parallel interface was retroactively renamed Parallel ATA (PATA); it is also widely known by the marketing names IDE (Integrated Drive Electronics) and EIDE (Enhanced IDE). The standard specifies a maximum cable length of about 18 inches (450 mm), so it is used almost exclusively as an internal interface.
40 PIN IDC MALE at the controller & peripherals
40 PIN IDC FEMALE at the cable
| Pin | Name | Dir | Description |
|---|---|---|---|
| 1 | /RESET | OUT | Reset |
| 2 | GND | - | Ground |
| 3 | DD7 | IN/OUT | Data 7 |
| 4 | DD8 | IN/OUT | Data 8 |
| 5 | DD6 | IN/OUT | Data 6 |
| 6 | DD9 | IN/OUT | Data 9 |
| 7 | DD5 | IN/OUT | Data 5 |
| 8 | DD10 | IN/OUT | Data 10 |
| 9 | DD4 | IN/OUT | Data 4 |
| 10 | DD11 | IN/OUT | Data 11 |
| 11 | DD3 | IN/OUT | Data 3 |
| 12 | DD12 | IN/OUT | Data 12 |
| 13 | DD2 | IN/OUT | Data 2 |
| 14 | DD13 | IN/OUT | Data 13 |
| 15 | DD1 | IN/OUT | Data 1 |
| 16 | DD14 | IN/OUT | Data 14 |
| 17 | DD0 | IN/OUT | Data 0 |
| 18 | DD15 | IN/OUT | Data 15 |
| 19 | GND | - | Ground |
| 20 | KEY | - | Key (Pin missing) |
| 21 | DMARQ | ? | DMA Request |
| 22 | GND | - | Ground |
| 23 | /DIOW | OUT | Write Strobe |
| 24 | GND | - | Ground |
| 25 | /DIOR | OUT | Read Strobe |
| 26 | GND | - | Ground |
| 27 | IORDY | IN | I/O Ready |
| 28 | SPSYNC:CSEL | ? | Spindle Sync or Cable Select |
| 29 | /DMACK | ? | DMA Acknowledge |
| 30 | GND | - | Ground |
| 31 | INTRQ | IN | Interrupt Request |
| 32 | /IOCS16 | ? | IO ChipSelect 16 |
| 33 | DA1 | OUT | Address 1 |
| 34 | PDIAG | ? | Passed Diagnostics |
| 35 | DA0 | OUT | Address 0 |
| 36 | DA2 | OUT | Address 2 |
| 37 | /IDE_CS0 | OUT | (1F0-1F7) |
| 38 | /IDE_CS1 | OUT | (3F6-3F7) |
| 39 | /ACTIVE | OUT | Led driver |
| 40 | GND | - | Ground |
Notes
- Direction is given for the controller relative to the devices (hard disks).
- Two devices can share one 40-pin cable as device 0 (“master”) and device 1 (“slave”); cable select (pin 28) lets each drive take its role from its position on the cable instead of a jumper.
- The original 40-conductor ribbon cable was later joined by an 80-conductor version — the extra wires are interleaved grounds that reduce crosstalk — required for the faster Ultra DMA modes (UDMA4 / Ultra DMA 66 and above).
- Transfer modes evolved from PIO and multiword DMA to Ultra DMA, up to UDMA6 (Ultra DMA 133, 133 MB/s); addressing grew from 28-bit LBA (137 GB limit) to 48-bit LBA.
References
- AT Attachment-3 Interface (ATA-3), ANSI X3.298-1997 — Working Draft X3T13/2008D Rev 7b — Technical Committee X3T13; Annex A connector and Table 5 signal assignments.