5 spiPWMio
5 : spiPWMio
- Author: Sönke Appel
- Description: A PWM input and PWM generator are configurable via input pins, readable via output pins, and accessible via SPI for read and write operations.
- GitHub repository
- Open in 3D viewer
- Clock: 12000000 Hz
How it works
This module provides a PWM generator on output pin 7 and a PWM reader on input pin 7. The PWM generator duty cycle is set by input pins [6:0]. The PWM reader output is reflected on output pins [6:0]. The period is assumed to be 20 ms, and the duty cycle can be adjusted between 1 ms and 2 ms.
When the SPI interface is not used, the module behaves as described above. When SPI is used, its behavior can be configured as described in docs/specification.md.
How to test
Loop back the generated PWM signal to the PWM input pin, then verify that the PWM configuration is reflected on the output pins.
External hardware
The design can be tested using a development kit. Optionally, use an oscilloscope to monitor the PWM signal and a signal generator to provide a test input on the PWM input pin.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | ipins[0] | opins[0] | |
| 1 | ipins[1] | opins[1] | |
| 2 | ipins[2] | opins[2] | |
| 3 | ipins[3] | opins[3] | |
| 4 | ipins[4] | opins[4] | spi_cs_n |
| 5 | ipins[5] | opins[5] | spi_mosi |
| 6 | ipins[6] | opins[6] | spi_miso |
| 7 | pwm_in | pwm_sig | spi_sck |