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ATA Bus Interface and ATA Commands
6-22 Quantum Fireball Plus AS 10.2/20.5/30.0/40.0/60.0 GB AT
After power on or following a reset, the drive initializes the Command Block
Registers to the values shown in Table 6-11.
Table 6-11
Table 6-11
Table 6-11
Table 6-11
Command Block Register Initial Values
6.6
6.6
6.6
6.6
REGISTER DESCRIPTIONS
REGISTER DESCRIPTIONS
REGISTER DESCRIPTIONS
REGISTER DESCRIPTIONS
The Quantum Fireball Plus AS 10.2/20.5/30.0/40.0/60.0 GB AT hard disk drives
emulate the ATA Command and Control Block Registers. Functional descriptions
of these registers are given in the next two sections.
6.6.1
6.6.1
6.6.1
6.6.1
Control Block Registers
Control Block Registers
Control Block Registers
Control Block Registers
6.6.1.1
6.6.1.1
6.6.1.1
6.6.1.1
Alternate Status Register
Alternate Status Register
Alternate Status Register
Alternate Status Register
The Alternate Status Register contains the same information as the Status Register
in the command block. Reading the Alternate Status Register does not imply the
acknowledgment of an interrupt by the host or clear a pending interrupt. See the
description of the Status Register in section 6.6.2.8 for definitions of bits in this
register.
Drive/Head
4
Drive/Head
A
N
1
1
0
LBA Bits 24–27
5
LBA Bits 24–27
A
N
1
1
0
Status
Command
A
N
1
1
1
Invalid Address
Invalid Address
A
A
X
X
X
1. N = signal deasserted
2. X = signal either asserted or deasserted
3. A = signal asserted
4. Mapping of registers in CHS mode
5. Mapping of registers in LBA mode
REGISTER
REGISTER
REGISTER
REGISTER
VALUE
VALUE
VALUE
VALUE
Error Register
01
Sector Count Register
01
Sector Number Register
01
Cylinder Low Register
00
Cylinder High Register
00
Drive/Head Register
00
FUNCTION
FUNCTION
FUNCTION
FUNCTION
HOST SIGNALS
HOST SIGNALS
HOST SIGNALS
HOST SIGNALS
Summary of Contents for FIREBALL PLUS AS 10.2
Page 12: ...About This Manual 1 4 Quantum Fireball Plus AS 10 2 20 5 30 0 40 0 60 0 GB AT ...
Page 16: ...General Description 2 8 Quantum Fireball Plus AS 10 2 20 5 30 0 40 0 60 0 GB AT ...
Page 61: ...Basic Principles of Operation Quantum Fireball Plus AS 10 2 20 5 30 0 40 0 60 0 GB AT 5 16 ...
Page 62: ...Basic Principles of Operation 5 17 Quantum Fireball Plus AS 10 2 20 5 30 0 40 0 60 0 GB AT ...
Page 162: ...Index I 4 Quantum Fireball Plus AS 10 2 20 5 30 0 40 0 60 0 GB AT ...