Joe Dowlen wrote:
>
>      Darryl,
>
>      I have been using a UV eraseable PIC14000 in my project. At first it
>      took only about 5 minutes to erase the chip.  After about 5 erasures
>      this time had increased to 10 minutes. Finally at about 20
>      erase/program cycles the chip FAILED to erase. I have _never_ had this
>      problem with other EPROM devices.
>
>      Maybe the guys at MicroChip would care to comment?
>
>      Joe_Dowlen@egginc.com
>
> ______________________________ Reply Separator
 _________________________________
> Subject: UV Pic problem
> Author:  pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU> at SMTP
> Date:    12/3/96 10:03 AM
>
> Dear All
>
> I am currently developing a PIC16C63 application. I am using a UV erasable
> part in the development phase. My problem is that my device will no longer
> erase after only 3 erase cycles. All the data appears to be 0.
>
> - Could this be a result of leaving the device to 'cook' for too long
>   in the eraser ?
>
> - Should I expect this from microchip devices ?
>
> As these devices are costing 25 pounds each, any ideas very welcome.
>
> I do have one other problem with this device. I am using the UART and am
 unable
> to clear the receive interrupt. I thought that reading the received data would
> clear the interrupt flag.
>
> In a test program I have the PIC connected to a terminal and on receiving a
> character from it it is echoed back. The receive works from an interrupt.
> After sending only one character it is continually echoed back to the
> terminal. I therefore assume that the interrupt is not getting cleared.
>
> Again any pointers gratefully taken.
>
> Thanks
>
> - DarrylI've 16C74A and 16C64 UV versions, never had that problem! Be sure
 that
you did not use CP fuse!!!