Post by thread:questions about PIC

Hi to all engineers. I would like to know more about my 8 questions 1. when you enable pull-up resisters are they really resisters if yes what value are they like 10k or some thing. 2. in short form card 16c62a when you see brawn out protection YES is this means it has this brawn out protection built in it you can enable it or disable it. 3. what it the idea of pic16c62a RA4 to be always open collector when you use it as output. 4. since pic has power on reset what is the idea of having reset pin that almost always pulled high. 5. when you program pics and you got error massage is this means pic was defective or I did some thing wrong. 6. when you use JW parts there is no frequency number on it is this means it is good up 20 MHZ. 7. when you use serial programing how many pics can be programed at the same times. 8. when you do serial number programing using PROMATE can you read the serial number after code protection on if not what is the idea to program serial number if you can not read it Andre Abelian thank you in advance ========================================== = http://www.compufire.com = = spam_OUTandreTakeThisOuTcompufire.com = = .....mcu-engineeringKILLspam@spam@compufire.com = = Andre Abelian: Engine Electronics, Inc.= = Tel 909-589-5485 Fax 909-598-5695 = ==========================================

Andre Abelian <andreKILLspamcompufire.com> wrote: > 1. when you enable pull-up resisters are they really resisters if > yes what value are they like 10k or some thing. Andre: The "weak pullups" are not actually resistors, but they act just like resistors with a value of approximately 20K. > 2. in short form card 16c62a when you see brawn out protection > YES is this means it has this brawn out protection built in it you > can enable it or disable it. Yes; the brown-out detection, on parts that include it, can be enabled or disabled via configuration fuses. > 3. what it the idea of pic16c62a RA4 to be always open collector > when you use it as output. Sometimes you just need an open-collector output... Among other things, it's useful for switching voltages larger than Vdd. > 4. since pic has power on reset what is the idea of having reset > pin that almost always pulled high. If you want an external device (like a watchdog circuit or something) to reset the PIC, you need a RESET pin. > 5. when you program pics and you got error massage is this means > pic was defective or I did some thing wrong. It could mean anything... On the PROMATE, it usually means that the socket module isn't aligned properly. > 6. when you use JW parts there is no frequency number on it is this > means it is good up 20 MHZ. Yes. > 7. when you use serial programing how many pics can be programed at > the same times. Just one... That is, you can't attach multiple PICs in parallel to one PROMATE. > 8. when you do serial number programing using PROMATE can you read > the serial number after code protection on if not what is the idea > to program serial number if you can not read it The PROMATE's "serialization" feature programs the serial number into the PIC's program memory as a series of RETLW instructions... The number can be read by the PIC just as numbers in any other lookup table can. -Andy === Andrew Warren - .....fastfwdKILLspam.....ix.netcom.com === Fast Forward Engineering - Vista, California === http://www.geocities.com/SiliconValley/2499

Hello All, >Hi to all engineers. >I would like to know more about my 8 questions >1. when you enable pull-up resisters are they really resisters if yes >what value are they like 10k or some thing. I think the resistance is in the form of the source to drain resistance of a series FET which can either be enabled (an appropriate gate bias applied) or disabled by the weak pull-up option. >2. in short form card 16c62a when you see brawn out protection YES is >this means it has this brawn out protection built in it you can enable it or disable it. Yes I think the suffix A indicates that the device has a built-in brown-out reset circuit. - (i.e the PIC16C65 has no BOR circuit whereas the PIC16C65A does). I don't think the BOR option can be disabled by any register settings. - I think that BOR is a feature that is desirable and would generally be required. >3. what it the idea of pic16c62a RA4 to be always open collector when >you use it as output. I'm not sure about this, but perhaps it is encorporated to allow I2C operation etc. or other circuit interfacing which requires open-collector buffering ??? >4. since pic has power on reset what is the idea of having reset pin >that almost always pulled high. The Reset must be pulled high for normal operation, but if a master reset button is required then the reset pin can be momentarily pulled low to provide such a facility. - (i.e. a soft re-boot type option in case of a software lock-up due to a power brown-out or such like). >5. when you program pics and you got error massage is this means pic was >defective or I did some thing wrong. Not sure about this, do you mean an assembly error ?, if so then the assembly program syntax is in error - (i.e. an incorrect instruction such as movwy or something) ???. It is unlikely that the PIC device is faulty unless there has been some prior electrical damage (i.e. over voltage or incorrect polorization) ? >6. when you use JW parts there is no frequency number on it is this >means it is good up 20 MHZ. Sory I can't help with this one ! >7. when you use serial programing how many pics can be programed at the >same times. Or this one ! >8. when you do serial number programing using PROMATE can you read the >serial number after code protection on if not >what is the idea to program serial number if you can not read it Or this one ! >Andre Abelian thank you in advance Sory I could not be more help. Lee Hewitt (Manchester ENGLAND) =================================================== Lee Hewitt Manchester ENGLAND Home E-Mail: EraseMELHewitt104spam_OUTTakeThisOuTaol.com University E-Mail: L.Hewittspam_OUTeee.salford.ac.uk =================================================== ========================================== = http://www.compufire.com = = @spam@andreKILLspamcompufire.com = = KILLspammcu-engineeringKILLspamcompufire.com = = Andre Abelian: Engine Electronics, Inc.= = Tel 909-589-5485 Fax 909-598-5695 = ==========================================