FET vs EEM

[JVimes 0]

Hi all,

 

Another newbie question: What's the differences in the roles played by a Flash Emulation Tool and the emulation done in the Embedded Emulation Module in my MSP430? It sounds like they both support debugging. Do they work together?

 

Thanks!

 

-JVimes

[roadrunner84 466]

Good question, I've never thought about it. The EEM is the part inside the controller that allows it to emulate code execution without having to flash the code in the flash memory. The FET is a programer/debugger, I doubt it will support actual emulation of the code inside itself, but rather communicate with the EEM in the target device to present a full emulation to the user.

[spirilis 1,264]

Yes, the EEM is the endpoint that the FET talks to in order to carry out its instructions. EEM has its tentacles deep inside the MSP430's processing core to access all the memories et al.

 

Sent from my Galaxy Note II with Tapatalk 4

 

 

[rockets4kids 204]

The use of the word "emulation" is archaic and is in no way appropriate to the way MCUs are used today.  TI should have dropped the term a decade ago, as it serves only to confuse just about everyone who wasn't using microcontrollers well over ten years ago.

 

Historically, re-programmable memory was very expensive so most chips used either ROMs that were masked directly onto the chip or one time programmable memories.  Even silicon was very expensive, so any debugging hardware at all was never included on the chips.  Development and debugging was done on dedicated boards that that either implemented the processor with discrete components or emulated it with a more advanced processor.  The program ROM was also typically emulated in RAM.  Because these development systems were very complex and only produced in relatively small volumes, they were typically very expensive.  Even at the very tail end of their use they still cost more than $1000.

 

However, new processes and technologies have made both FLASH memory and silicon cheap, and the cost to implement the hooks required to enable debugging on the chip itself add so little to the overall cost that just about all modern microcontrollers include them.  The MSP430FET is merely a communications bridge between the host and the on-chip debug hardware.