I would like to get some feedback on the importance of on-chip support for Debug/Emulation in 8051 processors. Originally the debug and emulation function were handled with bond-out devices. More recently there have been more efforts to move the debug functions on chip. Some parts are available with JTAG interfaces. So this brings up a few questions.
1. Why have 8051 been slow to adopt JTAG?
2. What level of debug/emulation/trace is expected for 8051 devices?
3. Is full trace important? Just PC trace?
4. What will be expected in 4 years for 8051 devices?
5. What is the minimum support that you would expect from a new device?
6. What would be your preference for all new 8051 devices?


Russell, If I recall, you are involved with designing the TI/BB series of '51 derivatives. The answer to the questions for a chip manufacturer really center on 3 things
a) are you interested in the 5 chip buyers
b) do you believe that cheap dev tools will make students remember you when they enter "real life" and actually BUY chips.
c) how much does it cost to integrate e.g. JTAG debug in a processor.

You will get a lot of answers "oh, please, let us have full ICE for $5" and if those 5 chip customers is of interest, then that is essential.


1) a) Low cost b) at 12 MHz etc emulation by ICE rather than on-chip is not a problem. c) those that matter (buying lots and lots of chips) have no problem with the cost of an emulatot (last I purchased, I bought 8).
2) Very deep if you are a big company, as deep as can be done cheaply if you are not.
3) yes, twice a year, thus I would not pay for it.
4) Something like the Philips SoftIce working and being adapted (an example, not a statement that SoftIce is the solution)
5) Compiler and ICE, Plug-in or on-chip
6) Low cost, high functionality


One thing you do not ask: ISP is, in my opinion, mandatory.

Erik