atsamd_hal::sercom

Module pad

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Expand description

Type-level tools to configure SERCOM pads

This module helps configure Pins as SERCOM pads. It provides type-level tools to convert Pins to the correct PinMode and to enforce type-level constraints at compile-time.

§Overview

A SERCOM pad is defined by two types, its corresponding Sercom instance and its PadNum, from Pad0 to Pad3. However, a given SERCOM pad can usually be mapped to several possible PinIds.

There are two primary traits defined in this module:

  • The IsPad trait is implemented on Pin types that are properly configured as SERCOM pads, with PinMode AlternateC or AlternateD. It acts as both a type class for SERCOM pads and as a type-level function to recover the corresponding Sercom and PadNum types from the Pin.
  • The GetPad trait maps each PinId to its corresponding, pad-related types. The PadMode alias uses GetPad to recover the corresponding PinMode for a given SERCOM pad, while the Pad alias recovers the configured Pin type.

§IOSET (SAMD51/SAME5x only)

SAMx5x chips do not allow arbitrary combinations of PinId for a given SERCOM. Instead, all PinIds must belong to the same IOSET. This module defines a [type-level enum], [IoSet], to enforce this restriction, and the [InIoSet] type class is responsible for labeling each IsPad type with its corresponding, valid IoSet(s).

Enums§

  • Pad0
    Type-level variant of PadNum representing SERCOM pad 0
  • Pad1
    Type-level variant of PadNum representing SERCOM pad 1
  • Pad2
    Type-level variant of PadNum representing SERCOM pad 2
  • Pad3
    Type-level variant of PadNum representing SERCOM pad 3

Traits§

  • GetPad
    Type-level function mapping PinIds to SERCOM-pad-related types
  • IsI2cPad
    Type class for Pins which can be used as I2C pads
  • IsPad
    Type class for Pins configured as SERCOM pads
  • OptionalPad
    Type-level equivalent of Option<Pad>
  • OptionalPadNum
    Type-level equivalent of Option<PadNum>
  • PadNum
    Type-level enum representing a SERCOM pad number
  • SomePad
    Type-level equivalent of Some(Pad)

Type Aliases§