Maxtor 2B010H1, 2B015H1, 2B020H1 Host Software InterfaceHost Software Interface, Host Software InterfaceHost Software Interface Host Software Interface

HOST SOFTWARE INTERFACE

6 – 1

SECTION 6

Host Software InterfaceHost Software InterfaceHost Software InterfaceHost Software InterfaceHost Software Interface

The host communicates with the drive through a set of controller registers accessed via the host’s I/O ports.

These registers divide into two groups: the Task File, used for passing commands and command parameters and

the Control/Diagnostic registers.

Task File RegistersTask File Registers

Task File Registers

The Task File consists of eight registers used to control fixed disk operations. The host accesses each register

by the I/O port address shown in this Task File register map:

I/O PORT READ WRITE

1F0h Data Register Data Register

1F1h Error Register Features Register

1F2h Sector Count Sector Count

1F3h Sector Number Sector Number

1F4h Cylinder Low Cylinder Low

1F5h Cylinder High Cylinder High

1F6h Drive/Head (SDH) Drive/Head (SDH)

1F7h Status Register Command Register

Data RegisterData Register

Data Register

Provides access to the drive’s sector buffer for read and write operations. With the exception of ECC byte

transfers (which, during Read long and Write long commands, are 8 bits wide), data transfers through the

Data register are all 16 bits wide.

Error RegisterError Register

Error Register

A read-only register containing specific information regarding the previous command. Data interpretation

differs depending on whether the controller is in operational or diagnostic mode. A power up, reset,

software reset, or receipt of a diagnostic command sets the controller into diagnostic mode. This mode

invalidates contents of the Status register. The contents of the Error register reflect a completion code.

Issuing any command (apart from a Diagnostic command) places the controller into operational mode.

In operational mode, the Error register is valid only when the Error bit in the Status register is set. The bit

definitions for operational mode follow:

76543210

0 ECC 0 IDNF 0 ABRT TK0 AMNF

Inter fa c e

CRC Data

ECC Error Not

Used ID

Not Fo und Not

Used Aborted

Command Track 0

Error Address

Mark Not

Found

Interface CRC – An interface CRC error occurred during an Ultra DMA transfer.

Data ECC Error – An non-correctable ECC error occurred during a Read Sector command.

Firmware Problem – Indicates a firmware problem was detected, (e.g., invalid interrupt, divide overflow).

ID Not Found – Either a matching ID field not found, or a CRC error occurred.

Aborted Command – Invalid commands, write fault, no seek complete, or drive not ready.

Track 0 Error – Track 0 was not found during execution of a Restore command.

Address Mark Not Found – The Address Mark could not be found after an ID match.

Features RegisterFeatures Register

Features Register

Enables or disables features through the Set Features command.