Post by thread:How do I read the 12C509 int osc cal value with my

I have a 12C508/JW and a 12C509/JW. I recall that on this list someone suggested reading and recording the internal oscillator calibration value stored at 0x1ff and 0x3ff respectively. When I use the Picstart Plus (PSP) only lets me read 0 to 0x1fe or 0x3fe. I did tell the PSP that I had a 12C509 and read the 12C508 to get the value at 0x1ff. How do I read the calibration value with my PSP for the 12C509?? - -Mark

On Mon, 13 Oct 1997 12:56:38 -0400 Mark Jurras <spam_OUTJURRAMTakeThisOuTTORRINGTON.COM> writes: >I have a 12C508/JW and a 12C509/JW. I recall that on this list someone >suggested reading and recording the internal oscillator calibration >value >stored at 0x1ff and 0x3ff respectively. When I use the Picstart Plus >(PSP) >only lets me read 0 to 0x1fe or 0x3fe. I did tell the PSP that I had a >12C509 and read the 12C508 to get the value at 0x1ff. > >How do I read the calibration value with my PSP for the 12C509?? > >- -Mark > Read the chip, then open the calibration values window (from the Window pulldown at the top of the MPLAB window). This little window will show one byte that is the calibration value, even though we know it is actually stored as a MOVLW at the topmost program location.

Depending on the version of MPLAB you are running with you may have to go into "Editor" mode from "Simulator" mode in "Development Mode" under "Options". So, to read/write the Calibration value, go to Editor mode, update the "Calibration Value" (as Mike describes below) then return to Simulator mode and then reload your project (I find I can't reassemble after doing this) and program as normal. Yah, it's a bit of a pain... myke {Quote hidden}>On Mon, 13 Oct 1997 12:56:38 -0400 Mark Jurras <.....JURRAMKILLspam@spam@TORRINGTON.COM> >writes: >>I have a 12C508/JW and a 12C509/JW. I recall that on this list someone >>suggested reading and recording the internal oscillator calibration >>value >>stored at 0x1ff and 0x3ff respectively. When I use the Picstart Plus >>(PSP) >>only lets me read 0 to 0x1fe or 0x3fe. I did tell the PSP that I had a >>12C509 and read the 12C508 to get the value at 0x1ff. >> >>How do I read the calibration value with my PSP for the 12C509?? >> >>- -Mark >> > >Read the chip, then open the calibration values window (from the Window >pulldown at the top of the MPLAB window). This little window will show >one byte that is the calibration value, even though we know it is >actually stored as a MOVLW at the topmost program location. > > Check out "Programming and Customizing the PIC Microcontroller" at: http://www.myke.com