PWM

This section introduces the Pulse-Width Modulation (PWM) APIs, including terms and acronyms, supported features, software architecture, details on how to use this driver, PWM defines, enums, functions and structures. More...

Overview

This section introduces the Pulse-Width Modulation (PWM) APIs, including terms and acronyms, supported features, software architecture, details on how to use this driver, PWM defines, enums, functions and structures.

Terms and Acronyms

Terms	Details
PWM	Pulse-Width Modulation.

Supported Features

• Normal Mode
  The PWM generates the fixed waveform at the specified frequency and duty. The application can query current frequency and duty in current mode. The PWM does not support interrupt mode.
  
• 2-state Mode
  There are two configurable states (S0 and S1) for PWM. User can set individual blink behaviors for these two states. User can also specify S0_stay_cycle to configure the stay cycles of S0.
• 2-state Replay Mode
  User can set replay mode with specified S0_stay_cycle and S1_stay_cycle. PWM would act as [S0->S1->S0->S1->S0... ].
• Differential Mode
  One PWM channel can be selected as the base channel. Other PWM channels can be selected as auxiliary channels in the same phase or reverse phase as the base channel.

How to Use This Driver

• SW Architecture:
  See Overview of M-HAL SW Architecture for details on the SW architecture. This section describes the definition of APIs and provides an example on FreeRTOS about how to use these APIs to develop an OS-related driver.
  
• The OS-HAL freeRTos driver sample code is as follows:
  freeRTos PWM sample code on github

Modules
	Define
	This section introduces the Macro definition which is used as PWM M-HAL's API error return type.
	Enum
	M-HAL PWM enumeration value list information, including define of the PWM channel number enumeration and define of the PWM running status enumeration.
	Function
	M-HAL PWM API list information, including PWM controller allocating and releasing, PWM hardware initializing and de-initializing, setting PWM frequency and duty cycle, enabling and disabling PWM hardware output, getting PWM frequency and duty cycle, getting the current status of PWM, enabling and disabling clock.
	Struct
	M-HAL PWM structure list information, including PWM controller structure, which used to store PWM controller resource.