Set Features Efh; Set Features (Ultra Ata/100); Table 6-25 Transfer/Mode Values - Quantum FIREBALL PLUS AS 10.2 Product Manual

6.7.25 6.7.25 6.7.25 6.7.25

Set Features EFh

Set Features EFh Set Features EFh Set Features EFh
The SET FEATURES command is used by the host to establish certain parameters
which control execution of the following drive features:
• 02h – Enable write cache feature
• 03h – Set transfer mode based on value in Sector Count Register
• 42h – Enable QDT mode
• 55h – Disable read look-ahead feature
• 66h – Disable reverting to power on defaults
• 82h – Disable write cache feature
• AAh – Enable read look-ahead feature
• C2h – Disable QDT mode
• CCh – Enable reverting to power on defaults
At power-on, or after a reset accomplished by either the hardware or software, the
default mode is 4 bytes of ECC, read look-ahead, and write cache enabled.
A host can choose the transfer mechanism by Set Transfer Mode and specifying a
value in the Sector Count register. The upper 5 bits define the type of transfer and
the low order 3 bits encode the mode value.
6.7.26 6.7.26 6.7.26 6.7.26

Set Features (Ultra ATA/100)

Set Features (Ultra ATA/100) Set Features (Ultra ATA/100) Set Features (Ultra ATA/100)
Set Transfer Mode Set Transfer Mode
Set Transfer Mode Set Transfer Mode
A host can choose the transfer mechanism by the Set Transfer mode, subcommand
code 03h, and by specifying a value in the Sector Count register. The upper 5 bits
define the type of transfer and the low order 3 bits encode the mode value.
PIO Default Transfer Mode
PIO Default Transfer Mode, Disable IORDY
PIO Flow Control Transfer Mode x
Multiword DMA Mode x
Ultra DMA Mode
Reserved
Key:
nnn = a valid mode number in binary
x = a mode number in decimal for the associated transfer type
Transfer/Mode Values
Table 6-25 Table 6-25 Table 6-25 Table 6-25
Quantum Fireball Plus AS 10.2/20.5/30.0/40.0/60.0 GB AT
ATA Bus Interface and ATA Commands
00000
00000
00001
00100
01000
10000
000
001
nnn
nnn
nnn
nnn
6-71