摘要 |
This adapter contains two separately controllable sections, each transferring data in various formats between a peripheral device interface and either a microprocessor contained in an associated I/O controller or a host processor or both. Dedicated controls enable the adapter to operate autonomously after being prepared by the microprocessor. Separate but interconnectable handshaking controls enable the sections to operate either asynchronously or in time coordination with each other. Handshaking controls in plural adapters are interconnectable to coordinate related transfers of data between a device and one or more hosts via plural adapter paths. Programmable commands enable the microprocessor to condition the adapter to conduct various data transfers autonomously. Such data can be transferred to or from the device interface in various bit-parallel formats defined by the commands, and from or to the host processor, the microprocessor, or both the host processor and microprocessor concurrently. In one handshaking mode, the adapter sustains an array indexing operation in which one section transfers "address" data to a device and the other section transfers "addressed" portions of a data array between the same device and either the host processor or the microprocessor.
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