摘要:
An analog-to-digital conversion module, QADC (1), and method minimize software involvement by providing a pause capacility. Each queue in the QADC (1) has one or more Conversion Command Words, CCWs (82), in a Conversion Command Word Table (62). Each conversion command word, CCW (82), has a Pause bit which can be used to create multiple sub-queues of A/D conversions without requiring the use of interrupts. The Pause bit can be used to place a queue in a pause state. When a queue enters a pause state, the scanning of CCWs (82) is stopped. The queue must then receive a trigger in order for the scanning of CCWs (82) to continue again.
摘要:
An analog-to-digital conversion module and method minimize software involvement by providing a programmable control table comprising a plurality of conversion command words (CCW's). Each CCW designates conversion parameters such as channel and reference selection, input sample time, and re-sample inhibit for one conversion operation, upon conclusion of which a digital value is stored in a corresponding result table. A set of CCW's defines one or more conversion sequences. Upon conclusion of each sequence, an interrupt can be issued and the result table may be read by an associated device, such as a CPU. If desired, the CCW sequence may be dynamically altered during operation of the conversion system.
摘要:
An analog-to-digital conversion system module and method provides programmable times for sampling analog input signals. Software involvement is minimized by providing a command word which includes information specifying a sample time. The command word may be stored in a register or memory table. The command word or words may specify the conversion time per analog input channel or group of channels, and per conversion or conversion sequence. In one embodiment a control table comprises a plurality of conversion command words (CCW's). Each CCW designates conversion parameters including the input sample time.
摘要:
An analog-to-digital conversion system module comprises a pin-limited A/D converter integrated circuit (I.C.) to which at least one multiplexer I.C. may be coupled and sampled.In one embodiment, host system software involvement is minimized by providing a sequence of sample commands, implemented by a channel sequencer or a programmable control table comprising a plurality of conversion command words (CCW's). A set of CCW's defines a conversion sequence which may be initiated and performed with minimal host system software involvement, upon conclusion of which a result table storing the converted digital values may be read by an associated device, such as a CPU.In one embodiment, some I/O pins of the A/D converter I.C. function either as analog inputs or address outputs to the external multiplexer, while other analog input pins alternatively function as single input channels or as combined channels from one or more external multiplexers. A software-loadable control register comprises a control field for a control word which determines the function of the programmable pins.