Programming. It seems to be proven that the clock MUST run in order for the PIC to be programmed (not verified for the erase function). THAT was the major source of problems seen. Why the h*ll a "verify" comes back when it is plain afterwards the PIC is blank i do not know. Maybe that is related to the fact that "Read" does nothing.
I have never seen that behavoir. Port pin RB6 is the serial clock for programming and must be driven by the programming adapter. The processor clock (whether internal RC, external RC, lf crystal, hf crystal etc) is
*not* required in either high voltage mode (13V on MCLR) or low-voltage mode (logic 1 on RB4 if config bit enabled).
piglet wrote in news:mtb6cc$gi3$ snipped-for-privacy@dont-email.me:
In fact on some older PICs, it is advisable to disable the clock during programming, if /MCLR is significantly loaded as transitions on OSC1 while /MCLR is rising to the minimum Vpp threshold can cause the program counter to increment and as it is used for programming mode addressing, this corrupts the code programmed by ofssetting its address. Its not an issue for current parts as entry into programming mode now resets the program counter.
There are also issues with reprogramming any PIC that has a running oscillator, and is loaded with code that has /MCLR disabled and uses the PGC and/or PGD pins as outputs, as the code may initialise the pins before the programmer can enter programming mode resulting in a level conflict.
If you need to disable a PIC RC or any crystal oscilator mode for programming, simply ground OSC1, however beware of two speed startup (IESO) or failsafe clock monitoring (FCM) being enabled in the CONFIG (if implemented) as the internal oscillator will thn take over. -- Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED) ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk [at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL
PITA. Trying various as well as outrageous code changes and seeing NO timing changes gets a bit hair-pulling.
Got it working. Problem is, if one makes changes in the code, you must use a NEW project name; otherwise code from previous time gets written. READ will work if you generate empty, new project.
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