topic Re: MC9S12XEG128 Tag RAM Question in S12 / MagniV Microcontrollers

MC9S12XEG128 Tag RAM Question

wb9ypa — Mon, 10 Dec 2018 20:33:31 GMT

There is very little mention in the documentation of what the Tag RAM is used for on the S12X series microcontrollers. I am ready to use the EEE on the S12XEG128 and successfully enabled the EEPROM emulation command. In the datasheet "Chapter 24 128 KByte Flash Module (S12XFTM128K2V1)" there is a paragraph that says: "Upon clearing CCIF to launch the Enable EEPROM Emulation command, the CCIF flag will set after Memory Controller enables EEE operations using the contents of the EEE tag RAM and tag counter." My question is: What do I need to do with the tag RAM? What data do I put in there if any? Anyone that can help I'll be so thankful!

Re: MC9S12XEG128 Tag RAM Question

wb9ypa — Tue, 11 Dec 2018 05:12:15 GMT

I think I've answered my own question. I have finally figured out how to use the EEE emulated flash and I am stoked! I'm having too much fun writing assembly on this awesome part (MC9S12XEG128). I guess I don't need to really be concerned about the tag ram. Writing to the emulated RAM automatically writes to the Flash memory now that I have everything written properly. The secret to the success of writing on this part is to read, read, and read the datasheets! I have included three photos of my project and I hope I can help someone else if they are having problems using the EEE using assembly coding. I also have both SCI ports working. One driving a vacuum florescent display and the other one connected to my laptop (dumb terminal). Hope you enjoy my photos. Thanks again NXP for supporting this excellent microcontroller. It will live a nice long life as an Amateur Radio (HAM) repeater system controller.

Truly yours,

mike

WB9YPA

Re: MC9S12XEG128 Tag RAM Question

dianabatrlova — Mon, 17 Dec 2018 10:02:21 GMT

Hi Mike,

I'm glad you solved your issue. Thank you for your comments, it can be useful for other customers.

Also, the AN3743 - Emulated EEPROM Quick Start Guide can be useful.

https://www.nxp.com/files-static/microcontrollers/doc/app_note/AN3743.pdf

or AN3490 - Overview of the MC9S12XE Emulated EEPROM

https://www.nxp.com/files-static/microcontrollers/doc/app_note/AN3490.pdf

Best Regards,

Diana

Re: MC9S12XEG128 Tag RAM Question

wb9ypa — Mon, 17 Dec 2018 12:44:24 GMT

Good morning Diana,

Thank you very much for getting back to me and the very helpful documentation on the Emulated EEPROM. Programming this part is like taking a fun ride in a high performance sports car. So many features and powerful instructions to get the number crunching done in a lot less time. I certainly hope these micros become as popular as apple pie!

All the best,

MIke

Custom Design Tech