I am trying to find a direct replacement of MC68HC705C8ACP . Question to all you geniouses,

[cineproducts]

I manufacture hand held instruments using the MC 68HC705C8 ACP chip. This part is discontinued does any body know if there is a new micro available which can be  direct replacement or similar with some software modifications.. HELP

Need Consultants in beautiful Los Angeles California.

[bigmac]

Hello cineproducts,

I wonder if there is some confusion over the change of part number for the device.  Since the introduction of RoHS versions, the part number of many devices has altered, but it is otherwise still the same part.

For the MC68HC705C8ACP, this is now MC705C8ACPE, with the final 'E' indicating that it is RoHS compliant.  This is still listed on the Freescale web site as "not recommended for new design", but is not yet discontinued.  I am still able to purchase the part through normal distribution channels.

Regards,

Mac

[glennp]

I have several tubes of PLCC44/QFN44  (have to check which) surface mount   C8 parts if your needs would be covered by them

glenn

(Australia)

[rocco]

Hi, Cineproducts:

I have built a dozen applications with the old HC705C8, and can safely say that there are no "direct" replacements. By 'direct', I mean parts that you can program with the same code, and drop into the same socket.

Over the years, I have migrated most of my HC05 designs over to the HC908 family. On some designs, I still use the HC05C8A. I still have stock, if your needs are small.

In general, features in the HC08 family are enhanced versions of those in the HC05C8A. However, nothing is similar enough that it doesn't require a little recoding.

I am in Long Beach, and if you really need help, you may PM me.

BTW: Digi-Key still has the MC68HC705C8ACP in stock, but they are over $10 each.

[peg]

Hi,

I have upgraded one particular product from HC05C8A to HSC05C8A to 908GP32 and then to S08GT16 and soon probably to S08GT16A. They are all very similar in capabilities and size.

My reason for changing was the requirement for more and more speed.

You are going to have to modify the firmware and the PCB so I would jump straight to the S08GTxxA as this is the best/cheapest/"most current" device. If you want to stick with through hole it is available in SDIP42.

Regards

David

[bigmac]

Hello Peg,

I would be interested to here how you would rate the S08AWxx series against the S08GTxxA.  The main differences that I can see would be -

1. Only one SCI port, versus two ports.
2. Capable of 5 volt operation, versus 3.3 volt operation only.
3. No through-hole package option for the AW series.

Are there any other differences that might influence the choice?  Perhaps current availabilty might be an issue.

Regards,

Mac

[peg]

Hi Mac,

I made the jump to GT before the AW was available.

They both have 2 SCI's!

I was able to convert the whole application to 3.3 volts.

I have used PLCC44/QFN44 all along.

In fact I made a couple of prototypes up by placing the GT on the PCB designed for the GP. Just a couple of cuts and jumpers, different regulator, 3491 in place of 491 etc

So I guess, after your comment, I would add to my previous response that if you want to stick to 5 volts then the AW is the go. It is very similar to the GB/GT.

Regards

David

[bigmac]

Hello Peg,

Yes, I missed the second SCI for the AW device - the block diagram in the data sheet has wide separation between the two SCI blocks.

I am not clear on the electrical differences between the GTxx and the GTxxA devices, but I notice that the A-suffix device appears to drop the through-hole package.  So this would leave the different supply voltage ranges as the only significant functional difference between the GTxxA and the AWxx devices - unless someone can enlighten me otherwise.

Therefore, the following rules might apply -

Require use of 5 volt peripherals - select AWxx device.

Require battery operation from single Li cell - select GTxxA device.

For all other cases, either device could be selected.

Regards,

Mac

[peg]

Hi Mac,

Look here for GT to GTA:

http://forums.freescale.com/freescale/board/message?board.id=8BITCOMM&message.id=3141

Regards

David