摘要:
To provide a data encoding circuit capable of securing real-timeness of a recording operation even in a memory of a low operation clock frequency by reducing the number of times of accessing the memory, and simultaneously reducing power consumption and memory costs. Prior to error correction encoding of a PI direction, error correction encoding of a PO direction is carried out at a PO arithmetic operation circuit (105), and an obtained PO code is added to corresponding data and written in a memory (101). Subsequently, data are read line by line in a PI direction from the memory (101) to a PI arithmetic operation circuit (110), a PI code is added to the data, and the data are sequentially output to a modulation circuit (200). Thus, it is possible to omit memory access when the data is read from the memory (101) to the modulation circuit (200) and memory access when the error correction code is written in the memory by the PI arithmetic operation circuit. As a result, it is possible to reduce an operation clock frequency of the memory.
摘要:
To provide a data encoding circuit capable of securing real-timeness of a recording operation even in a memory of a low operation clock frequency by reducing the number of times of accessing the memory, and simultaneously reducing power consumption and memory costs. Prior to its writing in a memory (101), data from a host is input to an EDC arithmetic operation circuit (110) and a scrambling arithmetic operation circuit (111) to be processed, and then the error correction codes are added to the data written in the memory (101) from the scrambling arithmetic operation circuit (111) by a PI arithmetic operation circuit (104) and a PO arithmetic operation circuit (105). Accordingly, it is possible to omit memory access when the data is written from the host in the memory, and memory access when the data is read from the memory to the EDC arithmetic operation circuit. Thus, it is possible to reduce an operation clock frequency of the memory (101).
摘要:
To provide a data encoding circuit capable of securing real-timeness of a recording operation even in a memory of a low operation clock frequency by reducing the number of times of accessing the memory, and simultaneously reducing power consumption and memory costs. Prior to its writing in a memory (101), data from a host is processed by an EDC arithmetic operation circuit (110) and a scrambling arithmetic operation circuit (111), and written in the memory (101). Next, error correction encoding of a PO direction is executed at a PO arithmetic operation circuit (105), and an obtained PO code is added to corresponding data to be written in the memory (101). Subsequently, the data are read in a PI direction line by line from the memory (101) to a PI arithmetic operation circuit (112). A PI code is added to the data, and the data are sequentially output to a modulation circuit (200). Thus, it is possible to omit memory access when the data is written from the host in the memory, memory access when the data is read from the memory to the EDC arithmetic operation circuit, memory access when the data is read from the memory (101) to the modulation circuit (200), and memory access when the error correction code is written from the PI arithmetic operation circuit in the memory. As a result, it is possible to greatly reduce an operation clock frequency of the memory.
摘要:
An address generating circuit (13) generates a reading address for reading a buffer memory (16) so that so-called P and Q codes for a CD-ROM which have parameters i and j can be decoded. The reading address is obtainable based on a formula RDA=H+2L+p, where H is a starting address of one block not inluding synchronous signal or pattern, L is a symbolic location of a symbol, and p is a sign for designating that the symbol is included in a LSB byte plane or an MSB byte plane. A first full adder (25) generates the symbolic location L based on the parameter i and j with various constants being given from a constant generator (23) so as to give the symbolic location L to a second full adder (21). The starting address H is given from a writing address pointer (12a). The second full adder adds H, 2L and p to apply the reading address to an address bus. In addition, the symbolic location L is latched in a symbol off-set address (26) and, if necessary, fed-back to the first full adder through multiplexers (24, 27) when the next symbolic location is to be generated.
摘要:
A disc recording/reproducing apparatus according to the present invention intermittently records and reproduces compressed digital audio data in normal recording/reproduction. In high-speed dubbing of digital audio data, two of such apparatuses are used, wherein compressed digital audio data is continuously reproduced from a disc for reproduction by the reproduction side apparatus to be directly applied to the recording side apparatus and continuously recorded on a disc for recording. Thus, the compressed high-speed dubbing of the digital audio data can be achieved without increasing a rotation speed of the disc even in high-speed dubbing.