AnsweredAssumed Answered

Help,The GDU doesn't work!

Question asked by chen qizhi on Feb 19, 2017
Latest reply on Mar 27, 2020 by Radek Sestak


Hi, I began to use S12ZVML in my project one year ago, it work well. but in recent Life Test, I meet some trouble.

Two controllers can't operate normally, I connected the mcu through P&E, found that the GDU went wrong(GDUF_GHHDF and GDUF_GHHDIF are set) and GUD cut off the output signal.

Refer to the s12zvm reference manual, It showed that "Voltage on pin HD is greater than VHVHDLA or VHVHDHA". But I get the ADC raw value from the internal adc channel(ADC1_Internal_3:GDU DC link voltage monitor),the register value is 34518(left aligned), it showed that:

Vhd = 34518 / 65536 * 25V =13.1V(in most data, for example Freemaster, shows that 25V is the range)

or Vhd = 34518 / 65536 * 60V =31.6V (in datasheet, because I set register GDU Phase Mux Register (GDUPHMUX)  0x00, it means: Pin HD selected , VHD / 12 connected to ADC channel)

which one is right?

P.S: I try to force clearing the bit(write 1 to GDUF_GHHDF ),but it didn't work. Can you help me to find the root cause of this error?



I looked for all information about the Vsup in reference manual. It was described:

"The VSUP pin can be routed via an internal divider to the internal Analog to Digital Converter.
Independent of the routing to the Analog to Digital Converter, it is possible to route this voltage to a
comparator to generate a low or a high voltage interrupt to alert the MCU."

But it didn't give the exact ratio of the "internal divider", I guess that the divider ratio is 1/5 from some application notes or example code, is that right or maybe it is pointed out in some other place or other document?


Best regards!