JP2828484B2 - Data recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a data recording / reproducing apparatus for recording and reproducing PCM data sent from a host computer using a rotary head type magnetic recording / reproducing apparatus or the like.

[Prior art] There is a rotary head type magnetic recording / reproducing apparatus for DAT (Digital Audio Tape Recorder).
Recently, a format for recording data for a computer using a rotary head type magnetic recording / reproducing apparatus for DAT has been developed.

FIG. 4 schematically shows a data recording method in this type of data recording / reproducing apparatus by a plan view of a magnetic tape T.

PCM data sent from the host computer is recorded for each group. This group has, for example, 22 frames, and the recording capacity of one frame is 5756 bytes. The data of each group consists of PCM data and an index area located at the back of the group, and furthermore ECC
The data is recorded. In this type of data format, data is recorded on the magnetic tape T as serial data for each group.

The host computer and the data recording / reproducing device are connected by a data bus such as a SCSI (Small Computer System Interface). In general, however, a single transfer between the host computer and peripheral devices such as the data recording / reproducing device is performed. The length of data transfer is determined so that the host computer is prevented from being in a connection state with a specific peripheral device for a long time.

[Problems to be Solved by the Invention] As shown in FIG. 4, data is recorded for each group on the magnetic tape T. And group B
In some cases. In this state, for example when attempting to transfer to the host computer reads the data units indicated by a, after reading a portion indicated by c ₁ of group A, is necessary to further read the region indicated by c ₂ Group B is there. However, at this time, group A and group B
It is expected that extra time will be required for reproduction in order to sandwich the seam portion between. For example, in the recording format of FIG. 4, since the portion indicated by b is an amble (dummy data), an opening time occurs when the head is scanning the portion b. When the recording state of the group B is bad, the retry is performed until the group B is completely read. However, the time required for the retry is also an open time. According to the conventional concept, since the data bus is connected until the data unit indicated by a is sent to the host computer, the opening time is wasted. In the recording operation, PCM data is sequentially sent from the host computer to the RAM of the controller and is stored in the group buffer in the RAM. For example, when the data buffer up to the group A becomes full, the buffer becomes full. The host computer, which continues to send the data unit indicated by a until opened, is kept connected via the data bus.

As described above, if the time for restraining the host computer during reproduction or recording becomes long, it becomes meaningless to determine the data transfer length from the host computer. That is, the host computer cannot be opened until the transfer of a predetermined unit of data to or from the host computer is completed, so that the processing efficiency of the entire system is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problem, and does not unnecessarily restrict the host computer at the time of recording or reproducing operation, even when data spans two groups. It is intended to provide a data recording / reproducing device.

[Means for Solving the Problems] A data recording / reproducing apparatus according to the present invention comprises: a recording / reproducing unit which records and reproduces PCM data divided into groups on a recording medium; A controller is provided for receiving or sending from the host computer via the bus, and a memory provided in the controller for storing PCM data to be recorded or reproduced is provided, and the memory includes a PCM for each of the groups. A group buffer for storing data, and a data area for organizing the PCM data stored in the group buffer into predetermined data units. A control unit for interrupting the connection of the data bus is provided. It is.

[Operation] In the above means, during reproduction, the data for each group read from the recording medium while the connection to the host computer is interrupted is stored in the group buffer of the memory, and the data in the group buffer is stored in the data area in the memory. Organize by data unit. After the completion of the data arrangement, it is connected to the host computer and sends the organized data to the host computer.

At the time of recording, data sent from the host computer in a predetermined unit is temporarily stored in the data area of the memory. Then, the connection with the host computer is interrupted. During this interruption, the data is divided into data for each group in the memory, and is recorded on a recording medium for each group.

Example An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a data recording / reproducing apparatus according to the present invention.

In the figure, reference numeral 10 denotes an SC connected to a host computer.
Shows the SI bus. Reference numeral 20 denotes a system controller, and reference numeral 30 denotes a recording controller. Although shown in a simplified manner, the system controller 20 processes and transfers data from the SCSI bus for recording. The recording controller 30 is for writing data in a predetermined format to the rotary head type magnetic recording / reproducing apparatus.

Reference numeral 12 denotes a CPU for controlling the system controller 20, and 13
Is a memory (RAM). Reference numeral 14 denotes a SCSI controller. The controller 14 is provided between the controller 14 and the SCSI bus 10 and performs protocol control and the like. Reference numeral 15 denotes a memory control circuit. 16 is a controller 3 for recording PCM data
PCM interface for sending to 0. Reference numeral 17 denotes a timing controller, which is built in the PCM interface 16, for example. Reference numeral 18 denotes an interface for sending a control signal to the recording controller 30.

Reference numeral 31 denotes a CPU for controlling the recording controller 30.
It is. The PCM data sent from the PCM interface of the system controller 20 is processed by a data processing circuit 32. The data processing circuit 32 forms a predetermined data format including an ATF and a subcode. Reference numeral 33 denotes an interface for receiving a control signal from the system controller 20.
The recording controller 30 has a capstan servo circuit.
34, a drum servo circuit 35, an ATF servo circuit, a tape loading control circuit (both not shown), and the like are provided.

In the rotary head type magnetic recording / reproducing device 40, Ha and Hb are magnetic heads. The magnetic heads Ha and Hb are mounted on a rotating drum. Reference numeral 41 denotes a recording / reproducing head amplifier. Reference numeral 42 denotes a capstan motor, and 43 denotes a drum motor.

FIG. 3 shows a memory map of the memory 13 provided in the system controller 20. The inside of the memory 13 is located in a group buffer, a data area, and a work area.

The group buffer has a memory capacity of 400 kilobytes, and when one frame of data of 5756 bytes is grouped into 22 frames, three groups can be stored. The data area uses a verify area or the like, and has a memory capacity of 32 kilobytes.

Next, as shown in FIG. 4, an operation in a case where a data unit a extending over two groups A and B is read from the magnetic tape T and transferred to the host computer will be described.

 FIG. 2 is a flowchart of the above operation.

When a data unit reception command indicated by a is issued from the host computer to the CPU 12 of the system controller 20 (step (a)), the connection of the SCSI bus is interrupted (Disconnect) under the control of the CPU 12 (step (b)). Group A and group B shown in FIG. 4 are sequentially read and stored in the group buffer of the memory map shown in FIG. When reading the groups A and B, an extra operation of reading the area of the amble b between the two groups takes extra time. Further, for example, when retry for reading the group B is performed, more time is required. However, at this time, since the connection of the SCSI bus 10 is interrupted, the host computer is released from the data recording / reproducing device. After the group A and the group B are read into the group buffer, the data unit a, which has spanned the two groups, is sent to the data area in the memory map under the control of the CPU 12, where it is organized as a set of data. (Step (c)). After this data is ready, it is connected to the host computer via SCSI bus 10 (Res
election) (step (e)). Then, the data unit a compiled in the data area of the memory 13 is sent to the host computer via the SCSI controller 14 and the SCSI bus 10. After the transfer of all data corresponding to the received command is completed, the processing operation ends (step (g)).
(H)).

 Next, the recording operation will be described.

Data from the host computer (for example, data read from a hard disk connected to the host computer) is transmitted from the SCSI bus 10 to the SCSI controller 14.
Is sent to the system controller 20 via At this time, the SCSI bus is connected only while the predetermined data unit a is sent, and after all the data is sent to the data area of the memory 13, the connection of the SCSI bus is interrupted (Disconnect) and the host computer is opened. . Then, the data stored in the data area is sent to the group buffer, divided into groups in the group buffer, and sent to the recording controller 30, as shown in FIG.
For example, the data unit a is recorded on the magnetic tape T in a state of straddling two groups.

The data recording / reproducing apparatus according to the present invention is not limited to the case of using a rotary head type magnetic recording / reproducing apparatus. It is possible to The system interface with the host computer is not limited to SCSI.

[Effects] As described above, according to the present invention, data spanning groups is arranged in the data area of the memory, and during that time, connection to the host computer is interrupted. Can be

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a data recording / reproducing apparatus according to the present invention, FIG. 2 is a flowchart showing a data reproducing operation, FIG. 3 is a schematic diagram showing a memory map in a memory, and FIG. FIG. 3 is a plan view of the tape schematically showing a state of recording data on the tape. 10 ... SCSI bus, 12 ... CPU (control unit), 13 ... memory, 20 ...
System controller, 30… Recording controller, 32…
Data processing circuit, 40 ... Rotary head type magnetic recording / reproducing device.

Claims (1)

(57) [Claims] 1. A recording / reproducing unit for recording and reproducing PCM data divided into groups on a recording medium, a controller for receiving or transmitting PCM data for each predetermined data unit from a host computer via a data bus, A memory provided in the controller for storing PCM data to be recorded or reproduced is provided, wherein the memory includes a group buffer for storing the PCM data for each group, and a memory for storing the PCM data in the group buffer. A data area for organizing the generated PCM data into predetermined data units, and the controller is provided with a control unit for interrupting the connection of the data bus while the data organization in the data area is completed. A data recording / reproducing apparatus characterized in that: