ATA PIO Mode: Difference between revisions
Jump to navigation
Jump to search
| [unchecked revision] | [unchecked revision] |
Content deleted Content added
| Line 297: | Line 297: | ||
Reading sectors using 48 bit PIO is very similar to the 28 bit method: |
Reading sectors using 48 bit PIO is very similar to the 28 bit method: |
||
(Notes: A sector count of 0 means 65536 sectors = 32MB. Try not to send bytes to the same IO port twice in a row. Doing so is <b>much</b> slower than doing two outb() commands to <b>different</b> IO ports. The important thing is that the high byte of the sector count, and LBA bytes 4, 5, & 6 go to their respective ports <b>before the low bytes</b>.) |
(Notes: A sector count of 0 means 65536 sectors = 32MB. Try not to send bytes to the same IO port twice in a row. Doing so is <b>much</b> slower than doing two outb() commands to <b>different</b> IO ports. The important thing is that the high byte of the sector count, features and LBA bytes 4, 5, & 6 go to their respective ports <b>before the low bytes</b>.) |
||
Assume you have a sectorcount uint16_t and a 6 byte LBA value. Mentally number the LBA bytes as 1 to 6, from low to high. |
Assume you have a sectorcount uint16_t and a 6 byte LBA value. Mentally number the LBA bytes as 1 to 6, from low to high. |
||