[SPAM bayesian] - Protecting Microcontrollers (was Re:[sdiy] converting a 10v p to p toa 0-5 volt signal) - Bayesian Filter detected spam

[Neil Johnson]

Hi,

Scott Nordlund wrote:
>> Another example: many Xilinx FPGAs have their programming pins run
>> off the 2V5 rails. But with current-limiting resistors it is
>> possible to program them from 3V3 drive (ref. Xilinx app notes on
>> programming Spartans).

> Ok, and in this case you'd be deliberately using these built-in diodes
> to implement the level shifting, with presumably no adverse  
> effects.  Makes sense, though for stuff that is less than  
> thoroughly documented, I might still prefer to take the paranoid  
> approach.


For a documented approach read Xilinx App Note xapp453:

http://www.xilinx.com/support/documentation/application_notes/ 
xapp453.pdf

Neil
--
http://www.njohnson.co.uk