JP2000267983A - Ata/atapi driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ATA/ATAPI driving device which is connected as a master drive with an ATA interface and makes a host device to exactly and promptly recognize a fact that a slave drive is absent when no slave drive is connected. SOLUTION: The ATA/ATAPI driving device is constituted by providing a task file register 4 for master in which a value to be responded to the host device in the case of confirmation of the master drive by the host device when a system is started is held and a task file register 5 for slave in which a value to be responded to the host device in the case of confirmation of the slave drive which does not exist by the host device is held and the fact that no slave drive exists is noticed to the host device by returning response to the host device by outputting the value of the task file register 4 for master when a master to an ATA bus 20 when the master of the ATA bus 20 is selected by the host device and outputting the value (FFh) of the task file register 4 for master to the ATA bus 20 when a slave is selected by the host device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CD-RO which is a computer peripheral device using an ATA interface.
M, DVD-ROM, DVD-RAM, CD-R / R
The present invention relates to an ATA / ATAPI drive device such as a W or HDD.

[0002]

2. Description of the Related Art There is an ATAPI (ATA Packet Interface) standard as a standard for connecting a drive other than a heart disk such as a CD-ROM drive or a DVD-ROM drive to an ATA interface for connecting a hard disk. The ATA interface has a primary and a secondary, and a master and a slave are prepared for each of the primary and the secondary (see FIG. 4). Therefore,
A total of four devices can be connected by the ATA interface. Normally, an AT compatible machine has a boot hard disk connected to the primary master,
ATA such as CD-ROM drive for secondary master
/ ATAPI drive is often connected.

ATA connected to ATA interface
The connection of the / ATAPI drive is recognized by the host device (host) when the system is started. Normally, the connection is checked in the order of primary master → slave → secondary master → slave. Each ATA /
Each ATAPI drive returns a response to the connection confirmation from the higher-level device, and the higher-level device recognizes this by a response from the ATA / ATAPI drive.

A response from the ATA / ATAPI drive to the host device is performed by outputting the value of a task file register defined by the ATA / ATAPI standard to an 8-bit data bus of the ATA interface. AT
In the API standard, the following values are defined as the initialization value of the task file register.

Status = 00h Error = 01h Sector Count (Interrupt Reason) = 01h Sector Number = 01h Cylinder Low (Byte Count High) = 14h Cylinder High (Byte Count High) = EBh Drive / Head (Drive Select) = 00h

[0006]

As shown in FIG. 5, in a situation where an ATA / ATAPI drive is connected as a master drive to an ATA interface and nothing is connected to a slave, the master drive of the master device is connected to the ATA / ATAPI drive. When the slave drive is confirmed following the recognition, the master drive releases the data bus of the ATA interface, and the signal on the data bus shifts from L level to H level with a time constant by a pull-up resistor. The host device confirms that the signal on the data bus is at the H level and recognizes the absence of the slave drive.

However, as described above, since the signal on the data bus shifts from the L level to the H level with a time constant by the pull-up resistor, the host device outputs the signal when the signal on the data bus does not reach the H level. In some cases, the data may be read, resulting in a problem that erroneous recognition occurs. It is not desirable to delay the timing of reading the signal on the data bus in order to speed up the system startup, and even if the above-mentioned time constant is reduced as much as possible to speed up the change of the signal, there is an error due to the limitation of the speedup. It was difficult to completely eliminate recognition.

The present invention has been made to solve such a problem, and it is intended that when an own drive device is connected to an ATA interface as a master drive and a slave drive is not connected, a slave drive is not present in a host device. It is an object of the present invention to provide an ATA / ATAPI drive device that can be recognized accurately and quickly.

[0009]

In order to achieve the above object, an ATA / ATAPI drive device according to the present invention comprises an ATA interface connected to a host device via an ATA interface.
/ ATAPI drive device, when its own drive device is connected as a master drive and the slave drive is not connected to the ATA interface,
The apparatus further comprises means for returning a response indicating the absence of the slave drive when confirming the slave drive from the higher-level device.

[0010] The ATA / ATAPI drive device of the present invention can make the host device accurately recognize that the slave drive is absent. For example, if the host device is A
When confirming that the signal on the data bus of the TA interface is at the H level and recognizing that the slave drive is not present, the ATA / ATAPI drive device of the present invention uses the data bus of the ATA interface to detect the absence of the slave drive. Is supplied as a response indicating the following. By doing so, the host device can accurately recognize that the slave drive is absent, regardless of the time from when the slave drive is selected to when the signal on the data bus is read.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an ATAPI CD-ROM of this embodiment.
1 shows a configuration of a portion according to the present invention of a ROM drive.

As shown in FIG. 1, the CD-ROM drive 1 is connected to an upper-level device (host) 10 through a primary or secondary ATA bus 20 of an ATA interface, and is connected to either a master or a slave of the ATA bus 20. Connected. 30 is a CD-ROM
An ATA interface connector for interconnecting the drive 1 and the ATA bus 20.

The CD-ROM drive 1 has an ATAPI
There is a CD-ROM interface decoder 2. This ATAPI CD-ROM interface decoder 2
Is a master task file register 4 in which a value that responds to the host device 10 when the host device 10 confirms the CD-ROM drive 1 as a master drive at the time of system startup; And a switching unit 6 for switching the values of the master task file register 4 and the slave task file register 5 in which a value responding to the host device 10 at the time of confirmation is held. The ATAPI / CD-ROM interface decoder 2 decodes either the value of the master task file register 4 or the value of the slave task file register 5 selected by the switching unit 6 into 8-bit data, and sends the 8-bit data to the ATA bus 20. It is configured to output.

FIGS. 2A and 2B show the configuration of each task file register 4, 5. FIG. The master task file register 4 holds the following values defined by the ATAPI standard as initialization values.

Status = 00h Error = 01h Sector Count (Interrupt Reason) = 01h Sector Number = 01h Cylinder Low (Byte Count High) = 14h Cylinder High (Byte Count High) = EBh Drive / Head (Drive Select) = 00h The slave task file register 5 holds the following value indicating that no slave drive exists.

Status = FFh Error = FFh Sector Count (Interrupt Reason) = FFh Sector Number = FFh Cylinder Low (Byte Count High) = FFh Cylinder High (Byte Count High) = FFh Drive / Head (Drive Select) = FFh Status, Error, Sector Count, Sector Number, Cy held in the task file registers 4, 5
Which of the values of Linder Low, Cylinder High, and Drive / Head is output to the ATA bus 20 is determined by five control signals defined by the ATA standard, but the description thereof is omitted.

Next, when the system is started, the host device 10
ATA / ATAPI connected to TA interface
The operation when recognizing a drive will be described.

The CD-ROM drive 1 has an ATA
It is assumed that the interface is connected as the master drive to the primary and the slave is not connected to the drive.

When the system is started, the CD-ROM drive 1, which is the master drive, uses the ATA standard DASP signal, PDIAG
Recognize using signals and the like. This CD is the master drive
-The ROM drive 1 validates the value of the master task file register 5 based on the result to enable the function of responding to the host device 10 when the slave device is selected from the host device 10. If a slave drive is present, the ATA bus 20 is set to be released when a slave is selected from the host device 10.

Thereafter, the host device 10 starts recognizing the drive connected to the ATA interface (ATA bus 20). Recognition of this drive is performed in the order of primary master → slave → secondary master → slave. When the master of the ATA bus 20 shown in the present embodiment is selected, the CD-ROM which is the master drive is used.
The ROM drive 1 reads the value of the master task file register 4, decodes the read value into 8-bit data, and outputs the 8-bit data to the ATA bus 20 to return a response to the host device 10. In response to this response, the host device 10 recognizes the CD-ROM drive 1 connected to the master.

Subsequently, the host device 10 selects a slave to recognize the drive connected to the slave of the ATA bus 20. At this time, this CD-RO which is the master drive
The M drive 1 detects that the slave has been selected by the host device 10, reads and decodes the value (FFh) of the master task file register 5, and outputs 8-bit data as the decoding result to the ATA bus 20. .
This notifies the higher-level device 10 that there is no slave drive. The host device 10 receives this response and recognizes that the drive is not connected to the slave.

Here, the difference in the recognition accuracy of the unconnected slave drive between the present embodiment and the conventional one will be described with reference to FIG.

FIG. 2 shows the ATA bus 2 after the host device 10 recognizes the master drive and then selects the slave.
The signal level changes above 0 are shown. In the figure,
The solid line shows the change in the signal level according to the conventional method. If the higher-level device immediately selects the slave after recognizing the master drive, the drive of the master that is actually connected releases the ATA bus, and the signal on the ATA bus is set to L level with a predetermined time constant by a pull-up resistor. (For example, 0 V) to an H level (for example, 5 V). When the host device selects the slave at time T0 and the host device reads the ATA bus signal at time T1, the ATA bus signal has not reached the H level. Cannot be detected. Since the signal of the ATA bus reaches the H level at the time T2, if the host device reads the signal of the ATA bus after the time T2, the presence or absence of the slave drive can be correctly detected. . But,
Delaying the timing of reading the signal on the ATA bus reduces the system startup speed.

On the other hand, in the system according to the present invention, the CD-ROM drive 1 as the master drive is
0 indicates that the slave is selected, and immediately changes the value of the master task file register 5 to the ATA bus 20.
ATA bus 2 as shown by the dotted line in the figure.
The signal level of 0 guarantees that the host device 10 has already reached the H level at the time T1 when the signal of the ATA bus 20 is read. For this reason, the host device 10 can reliably recognize the absence of the slave drive.

In this embodiment, FFh is held in the slave task file register 5 as a value indicating that there is no slave drive.
If a pull-up resistor is not added to the 7th bit of the TA bus 20, 7Fh may be held in the slave task file register 5 as a value indicating that there is no slave drive. As described above, the value set in the slave task file register 5 should be appropriately set according to the system.

Although the CD-ROM drive has been described above, the present invention relates to a DVD-ROM, a DVD-RAM,
It can be applied to other ATA / ATAPI drives such as CD-R / RW and HDD.

[0028]

As described above, the ATA / A of the present invention is used.
When the self-drive device is connected to the ATA interface as a master drive and the slave drive is not connected to the ATA interface, the TAPI drive device returns a response indicating absence of the slave drive at the time of confirmation of the slave drive from the higher-level device. The device can accurately recognize that the slave drive is absent regardless of the time from when the slave drive is selected to when the signal on the data bus is read.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a portion according to the present invention of a CD-ROM drive according to an embodiment of the present invention.

FIG. 2A is a diagram showing a configuration of a master task file register provided in the CD-ROM drive of FIG. 1;
FIG. 2B is a diagram showing a configuration of a slave task file register provided in the CD-ROM drive of FIG. 1.

FIG. 3 is a diagram illustrating a change in signal level on an ATA bus after a host device selects a slave after a master device recognizes a master drive, by comparing the present invention with a conventional example.

FIG. 4 is a diagram showing a form of drive connection to an ATA interface.

FIG. 5 is a diagram showing another form of drive connection to the ATA interface.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CD-ROM drive 2 ... ATAPI / CD-ROM interface decoder 4 ... Master task file register 5 ... Slave task file register 6 ... Switching unit 10 ... Host device ( 20) ATA bus 30 ... ATA interface connector

Claims (3)

[Claims] 1. An ATA / ATAPI drive device connected to a higher-level device by an ATA interface, wherein when the own drive device is connected to the ATA interface as a master drive and a slave drive is not connected to the ATA interface, ATA / ATA characterized by comprising means for returning a response indicating absence of the slave drive when confirming the slave drive.
PI drive device. 2. An ATA / ATAPI drive device connected to an upper device via an ATA interface, comprising: a master drive response value returned to the upper device when a master drive is confirmed from the upper device; A storage unit in which a response value for a slave drive returned to the higher-level device at the time of confirmation is stored; and a master drive from the higher-level device when the own drive device is connected to the ATA interface as a master drive and the slave drive is not connected. Means for returning a response value for the master drive stored in the storage unit when confirming, and returning a response value for the slave drive stored in the storage unit when confirming the slave drive from the higher-level device. ATA / AT
API drive device. 3. Before confirming the master drive from the higher-level device, it is determined whether or not the slave drive is connected to the ATA interface. Based on the confirmation result, the slave drive from the higher-level device is determined. 3. The AT according to claim 1, further comprising means for determining whether or not to respond to the confirmation of the AT.
A / ATAPI drive device.