1.3.11 Event System Interface (EVSYS)

The Event System (EVSYS) allows autonomous, low-latency and configurable communication between peripherals. Several peripherals can be configured to generate and/or respond to signals known as events. The exact condition to generate an event, or the action taken upon receiving an event, is specific to each peripheral. Peripherals that respond to events are called event users. Peripherals that generate events are called event generators. A peripheral can have one or more event generators and can have one or more event users. Communication is made without CPU intervention and without consuming system resources such as bus or RAM bandwidth. This reduces the load on the CPU and other system resources, compared to a traditional interrupt-based system.

Using The Library

Configure the EVSYS in MHC by adding a EVSYS channel and configuring the appropriate event generator. Add a event user and configure it to listen to the configured EVSYS channel. Make sure the involved peripherals are correctly configured to enable event generation and using the events in their respective peripheral configurations.

Library Interface

Event System Interface peripheral library provides the following interfaces:

Functions

Name	Description
EVSYS_Initialize	Initializes EVSYS module
EVSYS_GeneratorEnable	Enables EVSYS generator
EVSYS_GeneratorDisable	Disables EVSYS generator
EVSYS_UserEnable	Enables EVSYS user
EVSYS_UserDisable	Disables EVSYS user
EVSYS_InterruptEnable	Enables EVSYS interrupt
EVSYS_InterruptDisable	Disables EVSYS interrupt
EVSYS_CallbackRegister	Allows application to register a callback function

Data types and constants

Name	Type	Description
EVSYS_INT_MASK	Enum	Identifies the Event system interrupt to be enabled or disabled
EVSYS_CHANNEL	Enum	Identifies the channel to be used
EVSYS_CALLBACK	Typedef	Pointer to a EVSYS CallBack function