Re: TS-7200 Cirrus A/D converter calibration

[Craig Kulesa <ckulesa%loke.as.arizona.edu@localhost>]

Ken Hornstein wrote:

> So, according to the TS-7200 manual, the built-in EP93xx A/D 
> converters have been calibrated at the factory and calibration values 
> have been written to the EEPROM.  Okay, fine.  But the question I 
> have is ... where is this EEPROM?

You're talking to the Xilinx 9572 CPLD with those SPI calls to the 
EEPROM (on the last page of the TS schematics).   It's the same on both 
the TS-7200 and TS-7250.  The CPLD provides the glue logic needed to 
access a lot of the functionality of the EP9302, such as a working 
watchdog timer, ADC's, NAND flash and reset button handling.

The built-in Cirrus ADC works, but I recommend the MAX197 ADC for 
the TS-7200.  It handles larger (even bipolar) voltage inputs, has 
programmable gain and is a lot less finnicky.  For one thing, with 
the Cirrus ADC, you'll toast the entire ARM processor if you're 
incautious with your analog inputs!

On the TS-7260 and later products, I use the SPI bus lines to control an 
external ADC.  This is also possible on the TS-7200.

Speaking of 'later products', has anyone tried to boot the 
Marvell-Orion based TS-7800 with the orion_nas patches on -current?


Craig Kulesa
ckulesa%as.arizona.edu@localhost