TM4C1294KCPDT: History of this product line, LM4C, TM4C, etc.

Brian, TI bought the Stellaris line of microcontrollers from Luminary Micro.

http://www.ti.com/corp/docs/investor_relations/pr_05_14_2009_luminary_micro.html

jeff

May my tech group add:

• Luminary Micro Systems introduced the LM3S ("S" signifying Stellaris) family of ARM Cortex M3 MCUs.   External Fabs were employed for chip production.
• The "LM4C" devices were never "top-marked" as such - instead bearing LX4F markings, only.
• "TM4C123" devices followed the LX4F - and in some cases were (or near) "direct equivalents."
• "TM4C129" added capability - my group believes that no "direct and/or backward equivalents" exist.

We have a full slate of "chronologically introduced" Eval Boards - starting w/28 pin LM3S102, then OLED equipped LM3S811, rare BGA version of LX4F232,  soon followed by (same 232) but in QFP package.   All boards were "gifted" - our firm has been active here since (on/about) 2006...

Hello Brian,

I think you've gotten a pretty good picture already but to add from the TI side further:

The device family origins go back to Luminary Micro who made the LM3S series of devices. These are also the devices we refer to as the "Stellaris" family. This also was our entry point into the ARM Microcontroller (not to be confused with Processor) market. You might notice our programming software is named LMFlash Programmer. You can probably understand now where the LM comes from!

From there, as mentioned, there was plans for an LM4F set of devices which was a shift from M3 to M4 core. This is even seen in TivaWare where we have an EK-LM4F232 folder as one of the boards (to be removed from 2.2.0 and beyond). However, there were issues with the silicon before full production, hence only LX4F devices released to customers. The X nomenclature is common in TI MCUs which are not fully produced.

From TM4C errata for example:

XM4C — Experimental device that is not necessarily representative of the final device's electrical specifications and may not use production assembly flow.

TM4C — Production version of the silicon die that is fully qualified.

I will mention that this history occurred before I was around so I am not familiar enough about internal vs public knowledge to comment on the details with what occurred, so I'll leave that to the more knowledgeable community members who were around then to elaborate on from their POV.

Those events are what lead to the birth of TM4C portfolio. As Charles mentioned, TM4C123x was fully designed by TI, but as cb1 mentions, it also reused a lot of known good features from LM4F devices and the focus was addressing the known issues found in LM4F - hence the similarities present. Low power, Flash improvements, and adding a Floating Point Unit are some of the key additions with TM4C123x.

The TM4C129x family which also came out around this time then also added further unique differentiation with the integrated Ethernet PHY, USB High Speed support (with external USB PHY), and in some cases, security peripherals, LCD controller, EPI etc. As cb1 mentioned, there aren't any 'non-TM4C' equivalents for this device set. Also in those days, we were very low power in comparison to most (if not all) competition, that has changed of course.

When finished, TM4C came as the first released to production Cortex M4F cores by Texas Instruments. With TM4C also came a shift in brand from the Luminary brand of 'Stellaris' to the TI brand of 'Tiva-C'. Again, before my time, so I can't speak to the logics of the name choice of 'Tiva-C'... 

Hope that is what you are looking for overall. Thanks to all who helped contribute to this history!

By the way, on product pages, you can find some documentation about shifting designs from LM3S to TM4C for further insight on a technical level.

For example: http://www.ti.com/lit/an/spma049a/spma049a.pdf

Historical MCU Greetings,

Here's a photo of LMI's 2nd "Eval-Board" - this one featuring the LM3S811.  (and an OLED - as suggested by one here.)    Our group additionally designed/developed a BLDC Control Board (shown at photo's right) which "plugged-in" to an existing Power Stage - and employed another LM3S as the Motor Controlling MCU.