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From: Periproct on 16 May 2010 07:32
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect that
the PIC is in low voltage programming mode, hence RA4 is not being used as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration word
is 0. The book of words says that if I can auto identify the PIC with PPP it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).

I appreciate it is a long shot someone on here knowing my board and software
but is there something I'm missing regarding programming this PIC in HVP
mode so I can get my port RA4 back?

Regards, Nigel

From: Periproct on 16 May 2010 09:13


"Periproct" <Periproct(a)btinternet.com> wrote in message
news:OJCdnRHx4K2fRXLWnZ2dnUVZ8r-dnZ2d(a)bt.com...
> I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
> programmer with PPP ver 3.
>
> The PIC should be responding to an input on RA4 but it isn't. I suspect
> that the PIC is in low voltage programming mode, hence RA4 is not being
> used as an input.
> I have PPP set to disable LVP and I can see bit 7 of the configuration
> word is 0. The book of words says that if I can auto identify the PIC with
> PPP it is in LVP mode which is what I am getting.
> The board has the required 14V (I've upped the PSU to get that and the on
> board regulator isn't running hot and it is programming the PIC OK).
>
> I appreciate it is a long shot someone on here knowing my board and
> software but is there something I'm missing regarding programming this PIC
> in HVP mode so I can get my port RA4 back?
>
> Regards, Nigel
Just to add to my post.
Time is getting short as this is a school project that has to be in this
coming week. I can get a basic programmer (from Maplin in the UK) which
doesn't have the option for LVP. I'm wondering if, in desperation, this
might solve my problem.


From: Merciadri Luca on 16 May 2010 09:15
On May 16, 1:32 pm, "Periproct" <Peripr...(a)btinternet.com> wrote:
> I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
> programmer with PPP ver 3.
>
> The PIC should be responding to an input on RA4 but it isn't. I suspect that
> the PIC is in low voltage programming mode, hence RA4 is not being used as
> an input.
> I have PPP set to disable LVP and I can see bit 7 of the configuration word
> is 0. The book of words says that if I can auto identify the PIC with PPP it
> is in LVP mode which is what I am getting.
> The board has the required 14V (I've upped the PSU to get that and the on
> board regulator isn't running hot and it is programming the PIC OK).
According to http://www.voti.nl/swp/, applying a high voltage (around
14V) on the MCLR pin (input only) makes HVP. It seems that it is under
LVP, but then?

From: Periproct on 16 May 2010 09:17


"Merciadri Luca" <merciadriluca(a)gmail.com> wrote in message
news:ad118bb1-1121-41a3-b83f-8d2810df62a0(a)q23g2000vba.googlegroups.com...
> On May 16, 1:32 pm, "Periproct" <Peripr...(a)btinternet.com> wrote:
>> I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
>> programmer with PPP ver 3.
>>
>> The PIC should be responding to an input on RA4 but it isn't. I suspect
>> that
>> the PIC is in low voltage programming mode, hence RA4 is not being used
>> as
>> an input.
>> I have PPP set to disable LVP and I can see bit 7 of the configuration
>> word
>> is 0. The book of words says that if I can auto identify the PIC with PPP
>> it
>> is in LVP mode which is what I am getting.
>> The board has the required 14V (I've upped the PSU to get that and the on
>> board regulator isn't running hot and it is programming the PIC OK).
> According to http://www.voti.nl/swp/, applying a high voltage (around
> 14V) on the MCLR pin (input only) makes HVP. It seems that it is under
> LVP, but then?
>
Thanks for the reply. I'll try and put a meter on MCLR and see if it goes
high when it programs. Or is it the case I can use a bit of jumper wire to
apply 14V to that pin and force it to HVP.
Regards

From: Periproct on 16 May 2010 09:19


"Merciadri Luca" <merciadriluca(a)gmail.com> wrote in message
news:ad118bb1-1121-41a3-b83f-8d2810df62a0(a)q23g2000vba.googlegroups.com...
> On May 16, 1:32 pm, "Periproct" <Peripr...(a)btinternet.com> wrote:
>> I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
>> programmer with PPP ver 3.
>>
>> The PIC should be responding to an input on RA4 but it isn't. I suspect
>> that
>> the PIC is in low voltage programming mode, hence RA4 is not being used
>> as
>> an input.
>> I have PPP set to disable LVP and I can see bit 7 of the configuration
>> word
>> is 0. The book of words says that if I can auto identify the PIC with PPP
>> it
>> is in LVP mode which is what I am getting.
>> The board has the required 14V (I've upped the PSU to get that and the on
>> board regulator isn't running hot and it is programming the PIC OK).
> According to http://www.voti.nl/swp/, applying a high voltage (around
> 14V) on the MCLR pin (input only) makes HVP. It seems that it is under
> LVP, but then?
>
Another question is, does it have to be 14V or will a lower voltage be OK.


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