PT2000 mystery registers

[glenndoiron]

I am in the process of debugging some firmware for a solenoid driver board using a pair of PT2000 solenoid controllers.

There are three registers in PT2000 design studio, meas_func1 - meas_func3 @ 19Ah-19Ch, which do not appear in the data sheet.

I started the project by copying the project for the demo board, wiped the code and put in my own firmware.  On Channel3 Microcore0 I am using current sense block 6 to test if current starts flowing in the solenoid, and set an upper limit (this is for a solenoid being driven via voltage drive).

Permissions are set for CH3UC0 to have access to current block 6..

stadc off RIGHT_OC_TARGET; * (RIGHT_OC_TARGET = ossc)
stgn gain19.25 RIGHT_OC_TARGET;
stdm dac;
dfcsct DFCSCT_RIGHT; * use right side bridge current measurement (DFCSCT_RIGHT = dac6l)
...<snip>
load I_CURRENT_DETECT RIGHT_DAC_TARGET _ofs; * (RIGHT_DAC_TARGET = dac_ossc)
cwer STATE_VOLTAGE_DRIVE ocur row2; *I_COMP==1 (current detected)
wait row123; * FIRST WAIT STATEMENT.
* (The other wait entries are for START==0 (to terminate activation) and a
* a 7ms timeout to declare a fault if I don't see current.)
... <snip> (jr2 points to overcurrent fault routine)
load I_OVERCURRENT RIGHT_DAC_TARGET _ofs; * change I_COMP for overcurrent level
cwef jr2 ocur row2; *I_COMP==1 (overcurrent detected)
wait row12; * SECOND WAIT STATEMENT
* (Here the other row is just for START==0 to terminate the drive.)

 At the first wait statement, row2 is taken once solenoid current (75ma) is detected.

I then load in a 5.5A overcurrent limit, but the second wait immediately is taken and goes to the overcurrent fault error state.  Oscope/hall effect current probe on solenoid wires show no appreciable current.

I checked all the register settings, but had no description of the three mystery registers, which had settings still there from the original demo board project.  I went ahead and zeroed them out, recompiled... and suddenly it is operating as expected.

Why does the datasheet not have any description of these registers?  I need to know what they do so I can make sure that they are set correctly, as they are obviously affecting operation.

It should be noted that at this time I have autodiagnostic faults disabled (endiaga diagoff;)as I haven't gotten to shaking down the problems in my configurations for it).

[reyes]

Hi,

Those registers are described not in the datasheet but in application note because it is quite confidential. However, you can access app note from NXP DocStore (https://www.docstore.nxp.com/) and you will get the full description of the different registers and how to use them.

You can find the App Note document on NXP DocStore, you need to request permission to download it.

The proper process to get NDA protected documents is through DocStore because every document you download from this site is personalized with the data information of the person who download the document.

You can download it by yourself by following the steps below:

1. Go to https://www.docstore.nxp.com/

2. Log-in

3. Click on “Products” on the top of the page.

4. Click on “Powertrain and Electrification Analog Drivers” -> “Solenoid Controller” -> “PT2000”.

5. If you can’t see the Application Note”, then click on “Request Higher Access” to ask for permission.

This is the process to be followed by customers.

The permission to access these documents are approved by the Business Line directly (Products Engineers), unfortunately, I don’t have the permission to do it.

I would also recommend you to check what you have in the dac_settling time or in the filter lentgh to make sure that you take the loading time in account before checking the state of the comparator.

A simple test is to add some delay between load and wait instruction to see if it helps

This is done on register 196h