PIC32C series discussion thread

[rnd-ash]

Summary

This issue is to track and discuss the potential of adding support the PIC32C series to the crate.

The PIC32C series is Microchips successor to the ATSAM series of processors.

The PIC32C can be broken down into the following product lines:

• PIC32CZ CA - Cortex M7 - Meant to replace the SAMx7x series of chips (Inclusion of 5V tolerant digital IO)
• PIC32CK - Cortex M33 - Next generation of the PIC32CX SG line (See below)
• PIC32CX SG - Cortex M4F - Direct replacement to SAMx5x line (Same peripherals as ATSAMx5x). Binaries compiled for the SAMx5x series of chips does run on the PIC32CX SG.
• PIC32CM JH - Cortex M0+ - Direct upgrade to the SAM C21 series of chips - Pin compatible with SAMC21 series.
• PIC32CM LX - Cortex M23 - Upgrade to SAML10/11 series
• PIC32CM MC - Cortex M0+ - Feature compatible with SAM C20 chips
• PIC32CM GV00 - Cortex M0+ - SAMD21 replacement

Compatibility

From comparing datasheets, it appears Microchip was nice enough to either copy the previous generation SAMx peripheral sets, or, create 1 version of a new peripheral and use it across the lineup, meaning worst case, only 1 extra peripheral implementation would be needed for each peripheral (Like we have D5x and D11 implementations already in the crate).

As a glance, it appears the peripherals are split as follows (Microchip new denotes the new peripheral set that microchip has created, rather than peripheral sets present in the previous SAMx lineup, denoted as D5x or D11):

Chip	Peripheral impl
PIC32CZ CA	Microchip new
PIC32CK	Microchip new
PIC32CX SG	D5x 1:1 copy
PIC32CM JH	D5x - With some additions
PIC32CM LX	D5x - With some additions
PIC32CM MC	D5x - With some additions
PIC32CM GV00	D5x - With some additions

So looking at this, it appears the registers present in the D21/D11 are no longer used, since these are very old designs (2011-2012), so Microchip opted to use the D5x' register sets (2015) or create new ones for chips that they have redesigned from the ground up (PIC32CZ CA replaces the SAMx7x series (from 2010) that had dedicated SPI,I2C and UART rather than SERCOM peripherals)

[rnd-ash]

I've been testing the PIC32CX SG series lately, and it is 100% binary compatible with SAM5x line of chips. Everything seems to just work. The only thing that doesn't is flashing via probe-rs as Probe-rs doesn't know what this chip is. But, i can flash it by telling probe-rs it is a SAME5x chip with --chip ATSAME51J20A for example.

Maybe we can add a footnote to the crate about this specific chip?...

The only breaking difference is with the PIC32CX SG's that come with Microchips OTP Security module (SG 60 and SG 61). These chips have a second die which is an SPI OTP security module, hard wired to Sercom 3. Therefore, projects for SAME5x that use Sercom 3 are NOT compatible with these variants of the PIC32CX SG