Hi,
   I'm about half way through my "Program a PIC12C509A/JW Before Christmas Day" (ho hum) project and I've hit a major stumbling block. Specifically, the PIC12C5xx Programming Specifications Datasheet (Microchip doc# DS30557G) says the following on page 8:
CONFIGURATION WORD BIT MAP:
Bits 11-5: Reserved, write as '0' for PIC12C5XX

Now, if I program these bits as "0" using an "n" value of 100 (100uS Tpw * 100 attempts = 10mS - see pages 2 and 3), they read back as "1". For example:

WORD PROGRAMMED: 0x01A (MCLR on, CP off, WDTE off, INTRC osc)
WORD READ BACK:  0xFFA (MCLR on, CP off, WDTE off, INTRC osc)
This seems a little strange to me - surely if these bytes are programmed as "0", they should read back as "0" too. The 12C5xx databook says roughly the same thing about reserved bits in file registers - they should read back as "0". Can someone *please* tell me what I'm doing wrong here? Should I just add some code to the programmer driver to ignore bits 11-5 of the config word?

Thanks.
--
Phil.
philpem@dsl.pipex.com
http://www.philpem.dsl.pipex.com/

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