Semiconductor-Based Digital Data Storage Device Eliminates Moving Parts
Since Edison invented the gramophone, all recording and playback devices have required the same things: a recording medium and a device on which to play it. From vinyl records to eight-tracks to CDs, the principle has remained the same for over one hundred years -- an electromechanical device transfers data to a medium (cylinder, record, tape, floppy disk, or CD) which is then "read" with an electromechanical or optical device integrated with a moving transport system (turntable, tape capstan, and so forth).
The problem with these traditional devices is that they all incorporate moving components and, for the most part, physical contact between the medium and the playback system to recover the data, causing wear and tear over time. The result is increased maintenance costs as well as a loss of data integrity and playback quality as pickups, motors, and drive units wear out and become misaligned. Even CD players, with their optical pick-ups and lack of contact between the medium and the playback unit, require precise movements from several components that eventually succumb to repeated use.>
The use of moving parts has also placed constraints on the design and manufacture of these devices. For example, digital audio tape (DAT) systems require complex electronic servo control components to coordinate all their moving parts to maximize data transfer rates and maintain data integrity -- critical for data backup systems. Even simple CD players need a certain amount of space to house motor-driven spindle/turntable mechanisms that spin the disk past the optical pickup. All of this affects product size, complexity, and cost.
Further complications arise from vibration, shock, and playback position which affect the ability of devices such as CD-ROM players to operate, often causing them to shut down altogether. Even seemingly harmless things such as dust can damage playback surfaces -- tape heads, for example -- and degrade media.
Samsung has tackled these digital record and playback problems with a new technology that encompasses data recording and storage, record/playback, and playback only. All three systems use a combination of semiconductors, including Electronically Erasable Programmable Read Only Memory (EEPROM), read-only-memory (ROM) and random-access-memory (RAM). When integrated with digital signal processors (DSPs), digital-to-analog (D/A) converters, and computers, a new generation of record-and-playback devices is created with no moving parts and almost unlimited data capacity.
Here´s how it works:
For recording and storage, the system incorporates an EEPROM, a memory interface unit, and a RAM. To record data, a microcomputer tells a DSP to take data from the RAM and writes it to the EEPROM. To store the data, the DSP takes it from the EEPROM and sends it to the RAM. A RAM controller then reads the data from the RAM to the main computer via a SCSI interface.
For playback only (think MP3 players), a microcomputer instructs a DSP to take the digital information (for example, digital audio) from a ROM, then uses a D/A converter to create an analog output signal which it sends to an output terminal (headphones, for example) for playback.
To record and playback data (once again, digital audio), a microcomputer tells a DSP to take the data from a ROM, then uses a D/A converter to create either an analog input signal which gets recorded to an EEPROM or an analog output signal for playback through an output terminal.
With this semiconductor-based technology, design and manufacturing costs are reduced significantly and capacity increased dramatically over conventional media. Because all these devices have no moving parts and require no outside data medium, product designers using this technology have virtually unlimited options for system size and functionality.