TPL0102

Hi Bill,

This device does not automatically save the last wiper position if the code was only written to the volatile register.  Please read back the ACR to make sure that you are pointing to the nonvolatile memory.  You can also read back the nonvolative registers to confirm the values there are what you expect.

Best Regards,

Jim

If one writes 0xA0h, (assuming all address lines are pulled low),  0x00h, 0x##h (Where ## is the data).  The data  should be written to Non Volatile memory per the data sheet page 9 “TPL0102 Register Map”.  Furthermore, page 12 paragraph 2 states the IVR register should be saved.  Are you suggesting the only way to write to the Non Volatile memory is by reading back the ACR?  I also assume you must mean polling vol bit.

Hi Bill,

You are correct.  The command sequence you specified should write to the non-volatile memory, but only when the VOL bit is set low.  Note that this bit is low by default.

Since you are not seeing the expected value loaded from the non-volatile memory, I would first try to check the VOL bit and both the volatile and non-volatile registers to make sure that they are correct. 

If the registers are all correct, I would then check the setup that you are using to pulse the supply (assuming that you're using a supply pulse as the means of determining whether the wiper is being saved correctly).  If you have a large decoupling capacitor on the supply lines, please allow sufficient time for the internal nodes to discharge before bringing the supply back up.  If the supplies are brought back up too soon, the device may not recognize it as a POR condition (Note that if you're using bipolar supplies, both supplies need to turned off).

Hope this helps.

Best Regards,

Jim