1.2.23 Supply Controller (SUPC)

Using The Library

The Brown-Out Detector (BOD33) when enabled, monitors the VDD supply and compares the voltage with the brown-out threshold level. When VDD crosses the brown-out threshold level, the BOD33 can perform one of the following actions,

• Generate a reset

• Generates an interrupt

• Puts the device in battery backup sleep mode

The triggering voltage threshold for the BOD33 and the action can be configured via fuse bits in the NVM User Row. These bits can also be written after disabling BOD33. Brown out interrupt enables user to save critical data to prepare the system for a power-down.

SUPC Peripheral library provides non-Blocking API's and they can be used to perform below functionalities. Settings configured via MHC are written into SUPC registers when initialization function is called.

• Initialize BOD33, VREF and VREG of the SUPC peripheral.

• Set or clear OUTx pins of the SUPC peripheral.

Callback method

This example demonstrates how to get callback on brown-out detection to save critical work.

MY_APP_OBJ myAppObj;

void BOD_EventHandler(uintptr_t context)
{
    // The context was set to an application specific object.
    // It is now retrievable easily in the event handler.
    MY_APP_OBJ myAppObj = (MY_APP_OBJ *) context;

    // Brown-out interrupt occurred. Save critical data.
}

int main(void)
{
    /* Register callback function */
    SUPC_CallbackRegister(BOD_EventHandler, (uintptr_t)&myAppObj);

    while(true)
    {

    }
}

Library Interface

Supply Controller peripheral library provides the following interfaces:

Functions

Data types and constants