The Serial Peripheral Interface library is an abstract interface for bus managers and device driver support. the library contains bus manager implementations for hardware resources (AVR SPI and USI) and software using Ardino-GPIO.
The design of this library allows multiple bus managers both hardware and software, and device drivers directly support bus managers.
Version: 1.8
- Abstract SPI Bus Manager and Device Driver Interface, SPI
- Hardware SPI Bus Manager, Hardware::SPI
- Software SPI Bus Manager, Software::SPI
ATtiny variants.
Benchmarks measurements below do not include bus acquire-release (multitasking support), and slave select pin handling. The measurements are the transfer time in micro-seconds.
| Operation (LSB) | Bytes | us |
|---|---|---|
| transfer | 1 | 13.6 |
| transfer | 10 | 147.9 |
| transfer | 100 | 1491.8 |
| read | 100 | 1511.7 |
| write | 100 | 1459.6 |
| Operation (MSB) | Bytes | us |
|---|---|---|
| transfer | 1 | 12.8 |
| transfer | 10 | 139.0 |
| transfer | 100 | 1345.4 |
| read | 100 | 1304.2 |
| write | 100 | 1313.2 |
| Wiring (MSB) | us | SPI | us | Xn |
|---|---|---|---|---|
| shiftIn | 86.340 | spi >> var | 12.892 | 6.7 |
| shiftOut | 109.288 | spi << val | 13.144 | 8.3 |
| Wiring (MSB) | us | SPR | us | Xn |
|---|---|---|---|---|
| shiftIn | 86.340 | srpi >> var | 4.844 | 17.8 |
| shiftOut | 109.288 | srpo << val | 8.676 | 12.6 |
| Operation (LSB/MSB @ 8 MHz) | Bytes | us |
|---|---|---|
| transfer | 1 | 1.8 |
| transfer | 10 | 15.3 |
| transfer | 100 | 139.8 |
| read | 100 | 133.1 |
| write | 100 | 145.6 |
| Wiring (MSB) | us | SPI | us | Xn |
|---|---|---|---|---|
| shiftIn | 86.340 | spi >> var | 2.832 | 30 |
| shiftOut | 109.288 | spi << val | 2.832 | 38 |