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Real ICE and Vpp on new parts question

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mhanuel
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2009/03/11 23:04:48 (permalink)
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Real ICE and Vpp on new parts question

Hello to all dear forum users...

I have a doubt concerning the use of Real ICE with the new parts from Microchip that don't allow a voltage higher than 8 or 9 Volts on the Vpp pin.
I have heard about ICD2 and the need to clamp that voltage to allow compatibility but just want to be sure if the same applies for Real ICE.

Also, does any body knows where is the list of the new parts that need the new low voltage level on Vpp?

I will appreciate your comments,

Best,

Manuel
#1

11 Replies Related Threads

    Kiwi Mike AZ
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    RE: Real ICE and Vpp on new parts question 2009/03/11 23:10:21 (permalink)
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    There is not definitive list (Yet) of the parts.

    The only information I have received is "Any Part release in 2008 or later" and "Check the data sheet to be sure"

    I have not looked at the specs for the PICKit3, ICD3 or Real ICE to see if they have a programmable VPP (Easy to do, but dont know if they did)

    Mike
    #2
    Ken_Pergola
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    RE: Real ICE and Vpp on new parts question 2009/03/11 23:40:14 (permalink)
    +1 (1)
    Hello Manuel,

    The MPLAB ICD 2 tool (both RoHS and non-RoHS units) is the only tool that requires the Microchip 'Vpp Limiter' product (or a Vpp clamping circuit if one does not want to buy it) to keep Vpp under the maximum as called out in the Programming Specification for these parts.

    Therefore, you do not need the 'Vpp Limiter' product for the tool you have (the MPLAB REAL ICE).

    If my memory serves me right, the following families have a 9-volt maximum Vpp spec (which would require the Vpp Limiter product or a comparable clamping circuit on Vpp when using the MPLAB ICD 2 tool and the non-RoHS MPLAB PM3 tool):

    PIC16F727  Family
    PIC16F1937 Family

    PIC18F14K22 Family
    PIC18F14K50 Family
    PIC18F46K20 Family
    PIC24F16KA102 Family

    Expect the list tol grow longer.

    Microchip is sensitive to customer's tool investments so they made the decision to offer the 'Vpp Limiter' as a sellable product for MPLAB ICD 2 customers as a convenience. (I believe the circuit in the MPLAB IDE on-line help for anyone who wishes to make their own circuit.) This external Vpp clamping strategy was the only way to provide our MPLAB ICD 2 customers with a way to program these newer parts and to extend the tool's usefulness at the least cost to the customer. The option to re-design the MPLAB ICD 2 was not viable.

    Best regards,

    Ken
    post edited by Ken_Pergola - 2009/03/24 17:27:16
    #3
    mhanuel
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    RE: Real ICE and Vpp on new parts question 2009/03/12 08:07:48 (permalink)
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    Ken and Mike Thank you for your answers....

    I also have an old ICD2, don't wish to through away ten bucks in that piece of hardware, do you have a schematic of the clamping circuit, I look at the MPLAB IDE ICD2 help without success.

    Best,

    Manuel
    #4
    Ken_Pergola
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    RE: Real ICE and Vpp on new parts question 2009/03/12 11:45:56 (permalink)
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    Hello Manuel,

    Yes, I had trouble finding it too so I'm sorry about that.

    So to rectify that, I've just consulted with my colleague in Documentation and she will be adding 'AC164112' and 'Vpp Voltage Limiter' to the MPLAB ICD 2 help index to make it easier for customers to find this schematic (which is shown in 'ICDWarn0068').

    Please find the schematic attached to this post.

    Best regards,

    Ken





    post edited by Ken_Pergola - 2009/03/12 11:47:03
    #5
    mhanuel
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    RE: Real ICE and Vpp on new parts question 2009/03/12 19:57:11 (permalink)
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    Ken, I appreciate your support.
     
    Best,
     
    Manuel
    #6
    zamhxk
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    RE: Real ICE and Vpp on new parts question 2009/11/18 10:32:09 (permalink)
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    Can anybody tell me if I a series voltage regulator (i.e. with output of 8.2Vdc) can be used as voltage limiter? Because I just don't quite understand the benefits of using shunt regulator instead of series regulator? Please advice. Thanks. 
    #7
    RISC
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    RE: Real ICE and Vpp on new parts question 2009/11/28 17:06:12 (permalink)
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    Hi,

    You could do this more simply using a serial resistor and a Zener diode to limit ICD2 Vpp.

    regards
    #8
    zamhxk
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    RE: Real ICE and Vpp on new parts question 2009/12/17 15:37:37 (permalink)
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    Thanks Risc,

    I've done an ICD2 troubleshoot today, and found the difference of using shunt or serial voltage regulator for Vpp, i.e. only shunt regulators can be used (like the one you suggested). Because this Vpp should act as RESET line.
    #9
    rkvmkioji
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    RE: Real ICE and Vpp on new parts question 2010/03/05 06:07:26 (permalink)
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    Hello there,

    I've done this circuit to do a protection on MCLR but when I connect this circuit my program doesn't run and then I can't enter
    at the DEBUG mode. What can I do to solve this problem?

    I'm using PIC 16F1936 and ICD2 to debugger/programmmer.

    Thanks in advice.
    #10
    Ken_Pergola
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    RE: Real ICE and Vpp on new parts question 2010/03/08 22:29:20 (permalink)
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    ORIGINAL: rkvmkioji

    Rkvmkioji wrote:

    ===
    ...I've done this circuit to do a protection on MCLR but when I connect this circuit my program doesn't run and then I can't enter
    at the DEBUG mode. What can I do to solve this problem?...
    ===


    Hello Rkvmkioji,

    1) Please post the Vpp clamping circuit you are using (there's been talk of various methods in this thread so it makes it hard to know exactly what Vpp clamping technique you are referring to.)
    2) Also include how you have wired up the PIC16F1936 to the MPLAB ICD 2 tool.
    3) What version of MPLAB IDE are you using?
    4) Please post code snippet and configuration bits settings. You can ZIP up the project file and post if you feel comfortable doing that. From memory, I think it is 'Project' menu ==> 'Package in ZIP file' menu item.

    Best regards,

    Ken


    #11
    Ken_Pergola
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    RE: Real ICE and Vpp on new parts question 2010/03/08 22:48:31 (permalink)
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    Hello Rkvmkioji,

    Here's a quick test to try out. If you have enabled the Power-Up Timer enable bit during your debug session, try setting it to disabled.
    The following is from the MPLAB ICD 2 "read me" file.

    Release Notes for MPLAB® ICD 2
    In-Circuit Debugger & Development
    (Nonproduction) Programmer:


    ====
    If you cannot enter debug mode with one of the devices listed below, set the PWRTE (Power-Up Timer Enable bit) to DISABLED.

    PIC16F1937 / PIC16LF1937

    PIC16F1936 / PIC16LF1936

    PIC16F1934 / PIC16LF1934
    ====


    Best regards,

    Ken
    #12
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