From the sound of things you just need to look at the datasheet?.

But I'll repeat again (as usual) the 16F84 was replaced by the 16F628 last century, and you shouldn't be looking at using it.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

And, I'll repeat again that I cannot find anywhere on Microchips website that states the 16F84A is obsolete! On the 16F84A information page it clearly lists it's status as "in production".

Mike.

 

I didn't mention 'obselete'?, I mentioned that it had long been replaced by the 16F628 - which in my opinion renders it obselete anyway! - and it has long been listed as "not recommended for new projects".

From MicroChip's position they must be laughing all the way to the bank - selling an antique low spec chip for considerably more money than it's higher spec replacement!.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Microchip have never suggested that the 628 is a replacement for the 84 as evidenced by the lack of migration documentation (see here). I remember it being listed as "not recommended for new projects" but that listing has now changed to "in production" and so I must conclude that it is now usable for new projects. The only thing wrong with the 84 is erm, nothing, except it's slightly dearer.

I also think it is not very helpful to keep pointing out to posters that they are using older parts as a lot of people do not have access to newer pics due to where they live and/or school requirement etc.

Mike.

 

There certainly WAS a migration document!, it's so old now it's probably been removed?.

I notice that list also doesn't have a migration document for the 16C84 to 16F84 either, does that mean the 16C84 wasn't replaced either?. And, like the 16F628 migration document, there certainly was one back when it occurred.

I have no problem with people using old stocks they have (I still use 16C84's I've got knocking about), but people are buying 16F84's to use in new projects - if people don't tell them it's not a good idea, how do they know?.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Why would microchip remove documents?
But, it does have 16F83 to 16F84A and 16C622A to 16F628A, which would be from the same era. I remember seeing a document on Don McKenzie's site, is this the one you are thinking of?
That is the point, they don't need to know because it hasn't been replaced and there is nothing wrong with the 84. Anyone in production will use the cheaper alternative but the price/complexity issue just isn't worth it for the beginner.

The advantages of using the 84 far outweigh the slightly higher price for a beginner.

Mike.
edit typo.

 

For newcomers is good to make them aware about. Why not.

You realize that after some time dealing with all thsi stuff.

__________________
Agustín Tomás
In theory, there is no difference between theory and practice. In practice, however, there is.

 

Why is that?.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

1. There is such a vast amount of software readily available for the 84. I know that you only have to move the start of the variable area and write to CMCON to make it work on a 628 but that is far beyond most beginners and, if only the hex file is available, beyond a lot of experienced programmers.

2. There is a huge number of circuit that utilise the 84. You can tell beginners that it will work with the 628 with just a small mod to the source file. If they go ahead and build it, they will not know why it doesn't work because two things could now be wrong, the hardware or the mod to the code.

3. Most (probably all) of the simple programmers work with the 84.

4. Lots of school curriculum's are based on the 84.

5. The reason Microchip have not replaced the 84 is due to the above.

6. The 84 cost $2.71. The 628 is $1.29 - it just isn't worth the effort to save less than one pound.

7. There is absolutely nothing wrong with the 16F84A.

8. There only appears to be you that says it's been replaced with the 628.

Mike.

 

More then 200% for an inferior device!, and that's not a concern?.

No, apart from it's age, and the fact it was replaced years ago, for that matter there's nothing wrong with the 16C84 either.

And the MicroChip migration document!, and the "not recommended for new projects" which even you admit to seeing!. I'll see if I can find the migration document, I certainly downloaded it from MicroChip - but it's almost a decade ago now, so it depends if I have any backups left from back then? - certainly the hard drive it was on is long gone!

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

There not old, they still make brand spanking new ones and it's still not been replaced. The flash part was definitely a step in the right direction and Microchip don't supply the 16C anymore so they disagree with you there.
Yes, it was there, but microchip never said it had been replaced and they now appear to have reinstated it as a "in production" part. Maybe the "not for new projects" confused people into thinking it was either obsolete or had been replaced. As for the migration document, I'd be very interested to see it.

Whatever has gone before, Microchip now list the 84 as a production part and so it should not be refered to as obsolete or replaced.

I listed 8 reasons in order of most important first. You answered the last three.

Mike.

 

You are quite right. The newer pic chips are far superior to the earlier ones. However, the 16F84A was a revolution when it was released and will work from 2.0V to 5.5V and is still probably the best chip for a beginner. I personally use the 16F88 for most 18 pin work as I find it the most flexible. I just think the constant "your living in the last century" is unhelpful.

Mike.

 

The 16F84 isn't a FLASH part, it's an EEPROM based part - the sole reason for it replacing the 16C84 was due to the relatively poor protection on the 16C84 - which was why they even kept the same number.

No confusion, MicroChip actually stated it had been replaced by the 16F628, published a migration document, and listed the F84 as "not for new projects".

Due to the continuing demand, and the fact they can charge more than double for an inferior chip, possibly they have reinstated the F84?.

I'll keep looking for the migration document!.

Sorry, but none of them sounded very convincing? - we're not still using horses and carts, by that argument we should still be doing so!.

Converting 84 code to run on a 628 shouldn't be beyond a beginner, and converting even HEX code certainly shouldn't be beyond anyone with a slight amount of experience, never mind an 'expert'.

We probably shouldn't be destroying '4electros' thread, so I'll see about moving the offending posts to a new thread.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Microchip list it as an "Enhanced Flash/EEPROM" part.
I still maintain that Microchip never even hinted that the 628 replaced the 84. A search of the web didn't turn up any links to a migration document.
You have to be joking. Convert a hex file. Adding code to turn off the comparators may be simple. Moving the GPRs from 0x0c to 0x20 is next to impossible for most people.

Mike.

 

In Oz there is no price difference - the 84A and 628A are $9-95 each.
The 88 and 877 sell for $12-95.
All the major electronic retailers here continue to stock the 84A - I wonder how many they sell?

kenmac