John E. A. Wrote:
>>
You're exactly right. The RB3 pin is only used for low voltage
programming. While the chips come from the factory with this mode enabled=
,
in case you want to use it as your first programming method, the ICD (and=

all other commercial programmers that I know of) use the more traditional=

13v, programming method. So when you debug with the ICD its important to
disable this mode in the configuration word unless you take the
appropriate steps to prevent an inadvertent high on RB3, which will cause=

the device to stop running and go into programming mode.

Making this connection to the ICD isn't required since the ICD uses the
13v method. Its not recommended since it uses another one of your I/O pin=
s
that otherwise you could use for something else.
<<

Thanks. That makes things clearer. Reading the lit. I was getting the
impression that RB3 could not be connected to the target circuit and
had/had not to be connected to the ICD. I suppose given an application
where MCLR had to be kept below VCC the ICD could be switched to use RB3
instead but I gather this option isn't offered. I guess I should look bac=
k
at the errata about the header board and RB3 and see if it makes more
sense.