Post by thread:16C84 vs 16F84

Please excuse my confusion. What is the difference between the EEPROM 16C84 and the FLASH 16F84? I know the 'F has more RAM bytes, but aside from this, what's the practical difference? Is there any difference in programming, number of write cycles, etc? -Tony

Tony Brock-Fisher wrote: > > Please excuse my confusion. What is the difference between the > EEPROM 16C84 and the FLASH 16F84? I know the 'F has more RAM bytes, > but aside from this, what's the practical difference? Is there > any difference in programming, number of write cycles, etc? > > -Tony No differences, just another way to call the same thing. Bye

At 09:48 AM 1/16/97 -0500, you wrote: >Please excuse my confusion. What is the difference between the >EEPROM 16C84 and the FLASH 16F84? I know the 'F has more RAM bytes, >but aside from this, what's the practical difference? Is there >any difference in programming, number of write cycles, etc? > >-Tony 16F84 has PWRTE bit reversed (like ALL newer parts) when compared to the 16C84. All the spare config word bits in the 16F84 are used for code protection. The effect of code protecting a 16F84 is different from a 16C84. (If you want to know the esoterica of it all download the programming specs form the microchip web page but it usually is of little interest to the "man in the street.") Programming wise, you can program the 16F84 as a 16C84. Remember to reverse the code protect bit and don't expect code protection to be the same. Jim

Is the 16F84 a drop-in replacement for the 16C84? That is to say, I am currently using 16C84's in a product, programming them with a PIC16Cxx-PGM from Parallax, and using the Parallax assembler. I want to know if I can switch to 16F84 without updating my programmer or assembler..

-----Original Message----- From: NCSProduct <spam_OUTNCSProductTakeThisOuTAOL.COM> To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU <PICLISTKILLspamMITVMA.MIT.EDU> Date: Sunday, December 07, 1997 06:59 Subject: 16C84 vs 16F84 >Is the 16F84 a drop-in replacement for the 16C84? > >That is to say, I am currently using 16C84's in a product, >programming them with a PIC16Cxx-PGM from Parallax, >and using the Parallax assembler. > >I want to know if I can switch to 16F84 without updating my >programmer or assembler.. In almost all ways, the 16F84 is identical to the 16C84, about the only real difference from a programming point of view is the the power up timer bit is reversed, aside from that there are only good things, most notably it has twice the amount of RAM, a really good thing. TTYL

>I want to know if I can switch to 16F84 without updating my >programmer or assembler.. The answer is probably. There is more ram in the F84 so the assembler will not complile code for these extra locations. You cannot simulate the F84 on the older simulators for the same reason, and fuses are configured differently. (I forget which one). Tony Just when I thought I knew it all, I learned that I didn't.

On Sun, 7 Dec 1997 06:45:21 EST NCSProduct <.....NCSProductKILLspam.....AOL.COM> writes: >Is the 16F84 a drop-in replacement for the 16C84? > >That is to say, I am currently using 16C84's in a product, >programming them with a PIC16Cxx-PGM from Parallax, >and using the Parallax assembler. > >I want to know if I can switch to 16F84 without updating my >programmer or assembler.. Generally the F84 programs the same as the C84, but the Power-up Timer fuse is opposite in polarity. Also the Code-Protect is done differently. If you don't enable the Code Protect, and set the Power-up Timer to 'off' when it's supposed to be on, then the C84 programmer can program the F84. Both chips use the 14-bit core and same special function registers, so the same object code will work in either. But 32 of the file registers (0x30 to 0X4F) that were unused in the C84 are now live RAM in the F84. Unless the program is expecting these locations to read 0, a C84 program will just not use them, so it will work OK in a F84. Depending on how thoroughly the assembler checks the RAM allocations, it may not be possible to use the C84 mode to assemble a program that uses the extra RAM in the F84.

In a message dated 97-12-07 13:01:59 EST, you write: << In almost all ways, the 16F84 is identical to the 16C84, about the only real difference from a programming point of view is the the power up timer bit is reversed, aside from that there are only good things, most notably it has twice the amount of RAM, a really good thing. TTYL >> The Code protect bit is also reversed! Dave Duley

At 05:06 PM 12/8/97 +0000, you wrote: >In a message dated 97-12-07 13:01:59 EST, you write: > ><< > In almost all ways, the 16F84 is identical to the 16C84, about the only > real difference from a programming point of view is the the power up timer > bit is reversed, aside from that there are only good things, most notably it > has twice the amount of RAM, a really good thing. TTYL > > >> >The Code protect bit is also reversed! Does that mean if I change my assembly file from DEVICE PIC16C84,XT_OSC,WDT_OFF,PROTECT_ON to DEVICE PIC16C84,XT_OSC,WDT_OFF,PROTECT_OFF The 16F84 will be protected?

At 01:52 PM 12/8/97 -0500, you wrote: >At 05:06 PM 12/8/97 +0000, you wrote: >>In a message dated 97-12-07 13:01:59 EST, you write: >> >><< >> In almost all ways, the 16F84 is identical to the 16C84, about the only >> real difference from a programming point of view is the the power up timer >> bit is reversed, aside from that there are only good things, most notably it {Quote hidden}>> has twice the amount of RAM, a really good thing. TTYL >> >> >> >>The Code protect bit is also reversed! > >Does that mean if I change my assembly file from > > DEVICE PIC16C84,XT_OSC,WDT_OFF,PROTECT_ON >to > DEVICE PIC16C84,XT_OSC,WDT_OFF,PROTECT_OFF > >The 16F84 will be protected? No, the code protect bits are NOT reversed. There are more code protect bits and the codwe protection method is different but the code protect bits are not reversed. Jim Jim

As others mentioned the 16C84 and the 16F84 are compatible and you get the extra storage on the 16F84. As far as the programmer, which version of SPASM/SPEP are you using? v4.7 supports both parts. If you are using a version earlier than v4.6 you will probably need to update your programmer's firmware with a new chip. The upgrade is $39 which includes new manuals. Again, check your version. The v4.7 software is available free from Parallax's web site. When you run SPEP, it shows you all the devices your version currently supports. - Tom At 06:45 AM 12/7/97 EST, you wrote: >Is the 16F84 a drop-in replacement for the 16C84? > >That is to say, I am currently using 16C84's in a product, >programming them with a PIC16Cxx-PGM from Parallax, >and using the Parallax assembler. > >I want to know if I can switch to 16F84 without updating my >programmer or assembler.. > >