Direct Read and Write of datasheet register mnemonics in Arduino products sc.

I am a fiber optics engineer with lots of experience programming cpld / fpga in Verilog for controlling laser driven media converters. I also have experience writing automated test equipment command and control GUI’s in C#. I have had some experience in the past with embedded c when fpga was not an option. Although not my specialty, I was able to get by when working with uC’s by opening up the .h file and finding the mnemonics for the control and config registers the IDE would understand when the datasheet mnemonics wouldn’t.. With my experience and skill set in mind………….

My product is the MKR1010. What I want to do is to implement the PERIOD timer functionality of the MKR1010 SAMD21 as described in the Microchip datasheet page 673 called Period and Pulse-Width (PPW) Capture Action. I know I am not going to study the data sheet, configure a half dozen regs, hit go and sit back and smile. I am going to have to creep through Clock and TC blocks with baby steps confirming each configuration in vs out so I’m not looking for a solution but a method to directly write to the uC’s registers.

I have spent a week and a half of nights researching and trying these:

Bench testing every example sketch and video out there using counters of every imaginable method and none with any repeatability, precision, flexibility, and speed close to the hardware available on board.

Using TimerCounter block datasheet mnemonics in Arduino sketch – failed

Digging into the Arduino files trying to find any TC mnemonics the IDE would recognize – failed

Importing into Atmel Studio – failed It didn’t have a clue what to do with the spi, Wifinina and env libraries. I would love to use the mfgr IDE but I don’t have the advanced skill set to reverse engineer the libraries into the new IDE language. The spi and env reads would be easy but code level 802.xx, not me.

What am I doing wrong. Where did I take the wrong turn. What cave of scrolls have I yet to discover. Are we only limited to those few software functions on the reference page???

I cannot find any tutorials on register peek and pokes, only people with the same question I have.
How do we read and write directly to registers in Arduino products, in my case specifically the MKR1010???

Thank You Very Much for your time and assistance…………………………..