說明

• SPI Slave to PWM Generation Reference Design. Pulse width modulation (PWM) uses a rectangular pulse wave whose pulse width is modulated resulting in the variation of the average value of the waveform. Every PWM signal is a continuous succession of high and low pulses. In mobile phones and other consumer electronic products, the Light Emitting Diode (LED) is increasingly being used as a display backlight. PWM offers an ideal solution for LED controllers as the dimming intensity of the LED can be controlled by changing duty cycle and frequency of the pulse. This design provides a bridge between a Microprocessor and a PWM generator. The SPI slave interface is used to receive command data from an external SPI master. The command data in turn are used to set the frequency and duty cycle of the PWM. In this design the Embedded Function Block (EFB) in the MachXO2 device is used to generate the PWM signal