How to approach finding which micro controller include a specific sub-peripheral

Question

Broadly: An application I am working on requires a specific function of a common peripheral. I know that this function is optional in a big family, but short of visiting every single SKU's datasheet, how can I know which parts do include it?

Specifically, I need a "PWM fault input" which asynchronously and quickly pulls the PWM line low. Two families of the MSP430 microcontroller include a "Timer Event Control (TEC)" module (as seen in the MSP430x5xx and MSP430x6xx Family user guide Rev Q). However, this is only present on timer D, and I cannot find a way to search for that. Similarly, Microchip AVR chips may have a "Timer/Counter Type D" which does include this fault input. However, even going into something such as the AVR Microcontrollers Peripheral Integration Quick Reference Guide only tells you about how many 8 and 16 bit timers there are, which is not helpful as timer type D is 12 bits (other timers may be 12 bit too). No hints found on a supplier website such as digikey, as visiting two parts that include this functionality AVR64DD32 and MSP430F5172, you can see that in the peripheral section a generic "PWM" qualifier. I would like to also look at NXP MCUs, but at this point this is starting to be a big time sink.

The purpose of this question is not to get recommendations for MCUs that include this (although feel free to comment that), but I want to know what approach you may have to finding a generic function in a sea of microcontrollers, which may help in getting one that is more fitting for the overall application.

Answer 1

Most manufacturers recognise this problem, and hav e teams of pre-sales engineers to help you choose parts. Obviously you'll need a short list of manufacturers.

You may well find the "Contact-Us" or "Technical Support" of your manufacturers can be amazingly helpful. If you write to them with "I want this function as used on Chip ABC, which of your CPUs support it", you can often save an awful lot of time. Your success may vary a lot depending on what luck you have in individual sales engineers, but over the years I can say more are helpful than not. Often "I want to use your CPUs because of Feature X but I need feature Y from Competitor Model 99" triggers the exact response you hope for.

Answer 2

Each manufacturer tends to use their own acronym for the PWM fault function.
Your choice of manufacturer is likely influenced by other factors, which is the first way to reduce the search universe.

Be aware that manufacturers arrange their peripherals in a modular way - a PWM function is very often re-used across a family of their chips. It is useful to more closely examine the PWM function of a particular chip to see if your desired fault-shutdown is included. Then use their particular PWM acronym as a search term.

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For example, Microchip have a variety of PWM modules across a broad spectrum of microcontrollers. Some PWM modules are bare-bones and include no shutdown features. In a search, you might just see "Two PWM".
A more versatile PWM module by Microchip uses an acronym of ECCP: Enhanced-Capture-Compare-PWM. This module does include auto-shutdown. A search term through Microchip's families of ECCP should capture chips with this capability.

Another of Microchip's PWM modules uses an acronym of CWG: Complementary waveform generator. This one adds auto-shutdown to the generic PWM as well.

These search terms of ECCP and CWG would likely only apply to Microchip's families. The point is, find the appropriate acronym, and use these few search terms for a particular manufacturer.

Answer 3

I'm not sure if there is a standardized name for the term, the closest thing to it seems to be PWM emergency shut down input. Googling this term gives me lots of hits on microcontrollers. Although I don't think there's any way around reading the manual for the timer/PWM peripheral, per MCU.

Other than that, some timer/PWM peripherals support an "external trigger" function - as in taking input from an external signal would trigger the timer/PWM channels to flip to a certain level, which is essentially the same thing. Many MCUs also support a "force" option to immediately flip output compare/PWM channels to a level through software.