BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of the data storage method according to a preferred embodiment of the invention.
FIG. 2A is a block diagram of the optical storage device according to the first embodiment of the invention.
FIG. 2B is a chart of the memory 210 according to the first embodiment of the invention.
FIG. 2C is another chart of the memory 210 according to the first embodiment of the invention.
FIG. 3A is a block diagram of the optical storage device according to the second embodiment oft the invention.
FIG. 3B is a chart of the memory 310 according to the second embodiment of the invention,
FIG. 4 is a chart of the memory 210 according to the third embodiment of the invention.
FIG. 5A is a block diagram of the optical storage device according to the forth embodiment of the invention.
FIG. 5B is a contracted chart of the memory 510 according to the forth embodiment of the invention.
FIG. 5C is another contracted chart of the memory 510 according to the forth embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides an optical storage device and data storage method thereof. A buffer valid check device is used to check if the next written-in block is a valid block, and the optical storage device is accordingly controlled to stop writing data into a boundary of the block. At the dame time the data sent in from the previous class is temporarily stored in a buffer with less storage like an input data register and next operation is performed after the determination whether the next written-in block is a valid block. Therefore, the memory usage efficiency can be improved.
Referring to FIG. 1, a flow chart of the data storage method according to a preferred embodiment of the invention is shown. The data storage method is applied for writing a piece of data into a memory, such as a DRAM. The memory has a number of blocks.
The flow of reading data from disk according to the host request is described as follows. First, in step 100, read a piece of required data. Next, in step 102, temporarily store the piece of data into a buffer. Following that, in step 104, write the piece of data into a block of the memory. Then, in step 106, when writing the piece of data into the current block is finished, determine if the next written-in block of the memory is a valid block. The validity of the next written-in block would change according to a buffer pointer, which points the location of memory in which data read from disk will be stored, and/or a transfer pointer, which points the location of the memory from data will be transmitted to the host. Finally, when writing the piece of data into the block is finished and the next written-in block is the valid block, stop writing the data into the memory as shown in step 108. If the next written-in block is not the valid block, in step 110, continuously write the part of the piece of data into the next written-in block of the memory. When the data originally stored in the next written-in block is not transmitted, the next written-in block is defined as the valid block. Besides, the buffer in the step 102 may be a register or a SRAM.
The flow of writing data onto a disk according to the host request is described as follows Referring to FIG. 2A, a block diagram of the optical storage device according to the first embodiment of the invention is shown. The optical storage device 200 includes a pickup head 202, an input interface 204, a memory 210 and a memory control unit 212. The optical storage device 200 is coupled to a host 218. The pickup head 202 is controlled via the input interface 204 to read a piece of required data on a disk according to a request command of the host 218 wherein the piece of data can be also read from the host 218. For example when writing the piece of data on a disk, the piece of data is read from the host and written onto the disk after being encoded. The input interface 204 has in input data processor 206, and the input data processor 206 has a buffer 208. In comparison with the memory 210, the buffer 208 is a memory device with less storage for registering the data read by the pickup head 202. For example, the buffer 208 may be an input data register. The buffer 208, being able to be replaced by a SRAM, is used to be a buffer of the piece of data demodulated from the host to the memory 210.
The memory 210, such as a DRAM, has a number of blocks. The memory control unit 212 includes a memory access device 214 and a buffer valid check device 216. The memory access device 214 reads data from the buffer 208 and writes the data into a block of the memory 210. When the data is written into the boundary of the block, the buffer valid check device 216 checks if the next written-in block is a valid block. When the next written-in data is the valid block, the buffer valid check device 216 controls the memory access device 214 to stop writing the data into the next written-in block. When the next written-in block is not the valid block, the memo access device 214 continuously writes the left part of the data into the next written-in block. When the data originally stored in the next written-in block is not transmitted, the next written-in block is defined as the valid block,
In the above-mentioned optical storage device 200, when the next written-in block is the valid block, a flag is given to the next written-in block, and the buffer valid check device 216 determines if the next written-in block is the valid block according to the flag. Referring to FIG. 2B, a chart of the memory 210 according to the first embodiment of the invention is shown. In the memory 210, the flag given to the valid block is 1, and otherwise the flag is 0. Besides, the buffer valid check device 216 can also determine if the next written-in block is a valid block by using other methods. Referring to FIG. 2C, another chart of the memory 210 according to the first embodiment of the invention is shown. When writing data into the block is finished, the next written-in block is given a buffer pointer, and the block where the memory access device 214 reads data and sends the data to the host 218 is given a transfer pointer. When the buffer pointer equals to the transfer pointer, it represents that the next written-in block is a block where the memory access device 214 reads data and the data in this block has not transmitted yet. That is, the next written-in block is the valid block and writing data into the memory 210 should be stopped.
When the optical storage device is controlled by a defect management unit (DMU), not by the host, the above-mentioned data storage method is able to be applied. Referring to FIG. 3A, a block diagram of the optical storage device according to the second embodiment of the invention is shown. Compared with the optical storage device 200 in the FIG. 2A, the optical storage device 300 further includes a defect management unit 318. The defect management unit 318 is used to send out a request command to read the piece of data. Referring to FIG. 3B, a chart of the memory 310 according to the second embodiment of the invention is shown. For example, as reading a MRW disk, write the piece of data in the block 1 to block 6 of the memory 310 at the first time. If the block 5 is detected a defect, the block 5 is not the valid block. The complete data has to replace the block 5 but not to put a cover over the block 6 in the process of re-reading base to the mechanism of the linear replacement. Applied the data storage method mentioned above, setting the flag of the block 5 as 0 and otherwise as 1, it is able to stop writing data into a boundary of the block 5 without putting a cover over the block 6. Otherwise, it can reach the same purpose by applying a buffer pointer and a transfer pointer.
The above-mentioned data storage method is applied to a decoding process of an optical disk drive and can also be applied for an optical storage device such as a recorder to write data into a targeted disk. First, read a piece of required data from a host. Of course, the piece of data can also be read from a disk or a part of the data is read from the host and the left part of the data is read from the disk. Next, write the piece of data into a block of the memory is a valid block. Then, when writing the data into the block is finished and the next written-in block is the valid block, stop writing the piece of data into the memory. When the next written-in block is not a valid block, the left part of the piece of data is written into the next written-in block. Finally, write the piece of data into the targeted disk from the memory.
Mentioned to the above-mentioned data storage method, a least writing unit for writing the data into the targeted disk is N blocks, N is a positive integer. That is at least N blocks are written into the targeted disk once time. As the piece of data is written into the targeted disk by the host, have to read the left par of the data which is (N−m) blocks from the disk if the data is M blocks, wherein M=k×N+m, M, k and m are positive integers. The m blocks are not enough for N blocks. When the data of the least writing unit is enough and complete, the least writing unit will be written into the targeted disk after being encoded.
The above-mentioned data storage method largely improves the memory usage efficiency. Referring to FIG. 4, a chart of the memory 210 according to the third embodiment of the invention is shown. Take a blue ray disk (BD) for an example, the smallest block for writing data is called a cluster and each cluster includes 32 sectors. If only the data in the sixth sector of the third cluster of the disk is to be replaced, it needs only to be read from the disk the data in the region except for the sixth sector of the third cluster first and send from the host the data of the sixth sector of the third cluster to the memory. In the operation that the host sends data to the memory, the stop point for writing data should be controlled at the boundary of the block so as to prevent valid data from being covered. According to the data storage method of the invention, a flag or a pointer can used to determine whether the block is the valid block and whether to stop writing data into the boundary of the block. Therefore, the data storage method of the invention can largely improve the memory usage efficiency, not like the prior-art method, which wastes extra memory space for buffer and without need the operation of writing data into other memory first and then moving the data back.
Referring to FIG. 5A, a block diagram of the optical storage device according to the forth embodiment of the invention is shown. The optical storage device 500 is substantially equal to the optical storage device 200 of the first embodiment of the invention. An input interface 504 of the optical storage device 500 includes a data parser 506 and processing units 5081˜5083, including buffers 5084˜5086. The processing units 5081˜5083 is substantially equal to the input data processor 206, as buffers 5084˜5086 equal to the buffer 208. A pickup head 502 reads a piece of data on a disk. The piece of data demodulated by the data parser 506 is transferred to the processing units 5081˜5083 according to the property of the piece of data. After delays of the processing units 5081˜5083, the piece of data and some accessory signals generated will be written in the memory 510. The delays of the processing units 5081˜5083 are not the same. Assume that the delay of the piece of data of the processing units 5081 is longer than that of the processing unit 5082, as that of the processing unit 5082 longer than that of the processing unit 5083. The pace of the writing in memory 510 can be divided into two categories corresponding to whether the next written-in block is a valid block.
Referring to FIG. 5B, a contracted chart of the memory 510 according to the forth embodiment of the invention is shown. Because the delay of the processing unit 5083 is shorter, the piece of data transferred form it will be written to the boundary of the block n in advance. As the next written-in block n+1 is not a valid block, the piece of data of the processing unit 5083 could be written in the next written-in block n+1 in advance. Referring to FIG. 5C, another contracted chart of the memory 510 according to the forth embodiment of the invention is shown. As the next written-in block n+1 is a valid block, writing the pieces of data of the processing unit 5083 and the processing unit 5082 into the memory 510 should be stopped.
Moreover, it is able to check whether the next written-in block n+1 is a valid block until the processing units 5081˜5083 all write to the boundary of the block n. When the next written-in block n+1 is a valid block, writing the piece of the data of the processing units 5081˜5083 should be stopped. Otherwise, the pieces of data of the processing units 5081˜5083 should be written into the next written-in block n+1 in turn.
Taking an optical disk as example, the piece of data demodulated can be divided a subcode and a main data. As the main data is transferred into the processing unit that proceeds Cross interleaved Reed-Solomon Code (CIRC), the subcode is written into the memory 510 earlier for the shorter delay of the processing unit related. Assume that the subcode and the main data have respectively pointers as the targets of being written into the memory 510. When the subcode of block n is written, the subcode could be written into the next written block n+1 if the next written-in block n+1 is not a valid block before the buffers 5084˜5086 are full. After the main data of the block n is written, the buffer valid check device 516 is able to check whether the next written-in block n+1 is a valid block. If the next written-in block n+1 is not a valid block, the main data could be written in the next written-in block n+1.
In the optical storage device and data storage method thereof disclosed by the above-mentioned embodiment of the invention, the buffer valid check device is used to check if the next written-in block is a valid block, and the optical storage device is accordingly controlled to stop writing data into the boundary of the block. At the same time, the data sent in form the previous class is temporarily stored in a buffer and next operation is performed after the determination whether the next written-in block is a valid block. Therefore, the memory usage efficiency can be largely improved.
While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
Patent Application
20080065825
