Module pad

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§

IoSet1: Type-level variant of IoSet representing SERCOM IOSET 1
IoSet2: Type-level variant of IoSet representing SERCOM IOSET 2
IoSet3: Type-level variant of IoSet representing SERCOM IOSET 3
IoSet4: Type-level variant of IoSet representing SERCOM IOSET 4
IoSet5: Type-level variant of IoSet representing SERCOM IOSET 5
IoSet6: Type-level variant of IoSet representing SERCOM IOSET 6
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
UndocIoSet1: Type-level variant of IoSet representing an undocumented SERCOM IOSET
UndocIoSet2: Type-level variant of IoSet representing an undocumented SERCOM IOSET

Traits§

CommonIoSets: Type class for accessing the intersection of IoSets of OptionalPads Currently implemented for tuples of 2 and 4 elements
GetOptionalPad: Type-level function mapping OptionalPinIds to their corresponding OptionalPads
GetPad: Type-level function mapping PinIds to SERCOM-pad-related types
InIoSet: Type class for SERCOM pads in a given IoSet
IoSet: Type-level enum representing a SERCOM IOSET
IoSets: Type class for corresponding IoSet indices for OptionalPads, NoneT serves as a wildcard
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
ShareIoSet: Shortcut trait for Pad tuples that share at least one IoSet
SomePad: Type-level equivalent of Some(Pad)

Type Aliases§

Pad: Type alias to recover a Pin configured as a SERCOM pad in the correct PadMode
PadMode: Type alias using GetPad to recover the PinMode for a given SERCOM pad