Seagate ST3660A - Medalist 545 MB Hard Drive Product Manual page 35

Medalist XE Family Product Manual, Rev. B
3.3.2.1 PIO and DMA Data Transfer Modes
You can use the Set Features command to set the type of data transfer
mechanism and transfer mode that the drive uses. To do this:
1. Write Set Features command value 03
the Features register.
2. Write a Transfer Types value to the Sector Count register. The upper
5 bits of this value define the type of data transfer, and the lower 3
bits encode the mode value. The following table identifies allowable
Transfer Types values:
Data Transfer Mechanism
Mechanism name
PIO Transfer Mode (default:
Set PIO Mode = 2)
PIO Transfer Mode:
Set PIO Mode = 2
PIO Flow Control Transfer
Mode: Set PIO Mode = 0
PIO Flow Control Transfer
Mode: Set PIO Mode = 1
PIO Flow Control Transfer
Mode: Set PIO Mode = 2
PIO Flow Control Transfer
Mode: Set PIO Mode = 3
Multiword DMA Mode
Multiword DMA Mode
Reserved
Notes:
1. If the drive does not support a commanded mode, the drive
returns an Aborted Command error.
2. If the drive receives a Set Features command with a Mecha-
nism and mode value of 00000 001 and the drive supports
disabling of IORDY, then the drive sets its default PIO transfer
mode and disables IORDY.
Reserved values are intended for use in a future specification of an
alternative flow-control mechanism.
(Set Data Transfer mode) to
H
Transfer Types value
Mode Data
Lower 3 bits
value Upper 5 bits
2 00000
2 00000
0 00001
1 00001
2 00001
3 00001
0 00100
1 00100
— 01000
27
000
001
000
001
010
011
000
001
nnn