[SOLVED] Difference between PIC 16F876a and PIC 16LF876a

[gl1]

Hello,
Can you please tell me difference between 16F876a and 16LF876a?
I have prototyped a design with a 16F876a and all was ok. I could program successfully and toggle port pins...

I am now using 16LF876a in design and I am having problems getting 16LF876a to run with code that works and successfully programs on 16F876a.

Is there a special procedure i must follow to program. Are there differences in program word instructions? I believe all is similar between both devices.

thanks guys

 

[hexreader]

Hello,
Can you please tell me difference between 16F876a and 16LF876a?
I have prototyped a design with a 16F876a and all was ok. I could program successfully and toggle port pins...

I am now using 16LF876a in design and I am having problems getting 16LF876a to run with code that works and successfully programs on 16F876a.

Is there a special procedure i must follow to program. Are there differences in program word instructions? I believe all is similar between both devices.

thanks guys

What crystal frequency are you using?

The most obvious difference that I can see shown in the datasheet, is that the LF version only works up to 10MHz, while non-LF works up to 20MHz.

 

[gl1]

using 8MHz Xtal.

Perhaps I am not programming correctly, When PIC powered up and I check Xtal on scope it is running at approx 8MHz
I am using ICD2 to program device.

I cant think of anything else that could be wrong

 

[bigdogguru]

Can you please tell me difference between 16F876a and 16LF876a?

The PIC 16LF series have identical instruction sets, SFRs, etc. The advantage and only difference is the can operate with as little as 2V Vdd up to a FOSC of 4MHz and as little as 3V Vdd at a FOSC of 10MHz.

Reference pg 174, FIGURE 17-1: PIC16F87XA VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL, EXTENDED) VS FIGURE 17-2: PIC16LF87XA VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)

In Datasheet:

PIC16F87XA Data Sheet

As hexreader mention the PIC 16LF Series has a FMAX of 10MHz.

They were designed primarily for low power operations, such as batteries.

I am now using 16LF876a in design and I am having problems getting 16LF876a to run with code that works and successfully programs on 16F876a.

Is there a special procedure i must follow to program. Are there differences in program word instructions? I believe all is similar between both devices.

Did you change the FOSC, you mentioned you're currently using an 8MHz Xtal with the PIC 16LF876A, what was the FOSC on the PIC 16F876A?

Have you check your configuration settings? Made sure the appropriate system clock mode is selected?

I you upload or post your code one of us can take a look at it. A schematic of your design would be helpful as well.

 

[gl1]

Hi Guys,
I was programming with Low Voltage Programming Enabled,but it was not connected, therefore PICwould not enter programming mode
Thanks