Hello Jim,
It was not directly the answer that I expected for my question. I have
studied the schematics of the TS-7200 as well the MAX 192 datasheet,
from there it should be possibly to understand how the optional mounted
MAX192 would work. The datasheet describes that the HBEN is used to
select bits 8 to 11, however when this is not wired in the schematics,
it this wired on the board or is there any extention to the chip and
datasheet used?
Then I might comment your answer. I have checked the ts website,
www.embeddedarm.com, and they have demo code for the internal adc. If
you are aware of the TS code for Optional mounted MAX 197, I would to be
pleased for that link or information. What I found on TS page is: EP9301
on-board A/D converter sample code
<http://www.embeddedarm.com/downloads/samplecode/adc_72xx.tar.gz>
(04-17-2006) however that does not help me in the end to get all 12
bits of the external ADC.
And yes, I have read your code on your page. You maybe can explain how
you get the complete 12 bits from the optional max197 with just one
read, when the chip has only 8 bits ports with no HBEN. It the Cirrus
EP93xx doing some stuff in between or anything that I missunderstood?
You say in your code, adc_read that the value is: sv=*adc_io_read; where
the address point at adc_io_read=(unsigned short *)IOMMAP(0x10c00000).
However reading this once would give the 8 bit of max197? The difference
is that the internal ADC is possible to have all 12 bits read when it is
interfaced.
So question remains, what is done with HBEN on the external mouted
MAX197, to get all 12 bits?
/PO
Jim Jackson wrote:
>On Tue, 31 Oct 2006, Per-Olof wrote:
>
>
>
>>Hello,
>>
>>I have concerns how to use all the 12 bits on the MAX197 ADC on TS-7200.
>>According to the schematics the HBEN is not connected to any port or
>>function, and terefore it would not be possible to select to bit 8..11
>>form the conversion. Either I can't find any register or writing to
>>MAX197 that would enable the uppber bits.
>>Is it possible to use all 12 bits, or is the board just printed for 8
>>bit (and 8 channel)?
>>
>>
>
>I thought Technologics had put out some demo code for accessing the
>MAX197 on a ts7200???? Have you checked all the docs?
>
>As I've recently said on another thread on the MAX197 - you can check
>out my adc_logger and adio software referenced from my ts7200 webpage.
>
>Jim
>
>----------------------------------------------------------------------------
>HomePage: http://www.comp.leeds.ac.uk/jj
>TS7200 Page: http://www.comp.leeds.ac.uk/jj/linux/arm-sbc.html
>
>
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