Summary of expansion schemes
The following table summarizes the attributes of the different SPLat expansion schemes. Please note that this is a guide only, not hard and fast rules.
|
(2007) |
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|---|---|---|---|---|---|---|---|
TSP Discontinued |
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| Suitable for | Networking multiple controllers and dedicated peripheral boards | Smart I/O and communication functions | A few digital or analog I/Os | Bulk I/O or simple peripherals | Bulk, dumb digital I/O expansion | Intelligent peripherals | High-level onboard functionality |
| Based on | Half duplex serial data. Master/slave system | Spare processor I/O pins brought out to a connector. | SPI interface, SPx programming | SPx programming model but without SPx hardware | |||
| Number and type of I/Os | Practically unlimited | Limited by board size. Can be complex | Depends entirely on the controller board | Open-ended (none for Virtual SPx) | |||
| Programming | Simple configuration, then simply exchanges data automatically in background | Special TSP communication instructions | Appear as simple I/O points. Same as basic SPLat programming | Simple instruction to block transfer 1-20 bytes | Automatic configuration. Appears like normal onboard I/O | Register/command based programming model. The peripheral can provide high level functionality but usually requires a sophisticated programmer. | |
| Number of possible add-ons | Depends on cabling length | 1 | 1 | Usually only 1 | Several, depending on the details | Determined by custom board specification | |
| Mechanical | Separate boards, simple wiring. | Plugs onto a standard board. Can also be designed to work on the end of an extension cable | |||||
| Power supply | Usually requires power supply to its own specs | Usually from host SPLat board | Usually requires power supply to its own specs | ||||
Notes:
- TSP and Xwire are implemented only on selected standard and custom controllers. Please refer to individual product documentation.