1. Field of the Invention
The present invention relates to an apparatus for testing a controller using random pattern generation techniques. More particularly, the present invention relates to an apparatus for testing an integrated drive electronics (IDE) controller model by use of a computer simulation environment.
2. Description of the Related Technology
An IDE controller is a device which controls the flow of data traffic between the main memory of a computer system and one or more peripheral devices, coupled to the computer system via the IDE controller. One such peripheral device, for example, is an IDE disk drive. When employed in a personal computer system, an IDE controller must be proven to operate with many different types of IDE devices, such as hard disk drives, CD ROMs, etc. A typical IDE controller has many programmed modes of operation which must be tested to effectively verify that the IDE controller functions for its intended purpose. Therefore, it is necessary to test combinations of many parameters in order to ensure compatibility with all such disk drives. Also, variations in speed and features are numerous in modern IDE disk drive models making the design of an IDE controller that properly functions with these operational variations even more difficult. An apparatus for testing IDE controllers, commonly known as a "test bench," may test, for example, combinations of the following parameters: 1. Drive Transfer Mode (single-word DMA, multi-word DMA, synchronous DMA, programmed IO); 2. Drive Under Test (master or slave drive); 3. Timing Parameters (command pulse width, relaxation time, set-up time, pause time); 4. Transfer size (16 or 32 bit-wide transfers, number of sections); 5. Prefetch or Read Ahead Mode (enabled, disabled); and 6. Bus Mastering constraints (PRD, memory starting address, transfer byte count, single/multi-PRD transfers).
Previous methods of testing IDE controller designs required an on-line human operator to choose a particular combination of test constraints for each individual test case. After a particular combination of constraints was tested, the operator would then formulate another combination of test constraints and run that test, and so on. This "human centered" approach to IDE controller testing is cumbersome and often results in inadequate testing of an IDE controller due to human error or a lack of human resources. Therefore, a more efficient and comprehensive method of testing IDE controller models is needed.