Seagate Medalist 2520 Product Manual page 41

Medalist 2520 Product Manual, Rev. A
3.2.2.1 PIO and DMA data-transfer modes
You can set the multiword DMA mode and identify the PIO data-transfer
mechanism and transfer mode with the Set Features command. To set
the multiword DMA mode:
1. 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.
This changes word 63 of the Identify Drive command to the mode you
enter in the Sector Count register.
The following table identifies allowable transfer types values:
Data-transfer mechanism
Mechanism name
PIO Transfer Mode (default)
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
PIO Flow Control Transfer
Mode: Set PIO Mode = 4
Multiword DMA Mode
Synchronous DMA Mode
Note. If the drive does not support a commanded mode, it returns a 04
aborted command error.
(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
4 00001
0 00100
1 00100
2 00100
0 01000
1 01000
2 01000
33
000
001
000
001
010
011
100
000
001
010
000
001
010