Seagate Medalist 1270 Product Manual page 40

32
3.2.2.1 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. 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 low order 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
PIO Flow Control Transfer
Mode: Set PIO Mode = 4
Multiword DMA Mode
Multiword DMA Mode
Multiword DMA Mode
Reserved
If the drive does not support a commanded mode, the drive returns an
Aborted Command error.
Medalist 1270 Product Manual, August 1995
(Set Data Transfer mode) to
H
Transfer types value
Mode Data
value Upper 5 bits
2 00000
2 00000
0 00001
1 00001
2 00001
3 00001
4 00001
0 00100
1 00100
2 00100
— 01000
Lower 3 bits
000
001
000
001
010
011
100
000
001
010
nnn