Several Questions for S12ZVM

young-kyunpark — Tue, 21 Oct 2014 11:06:43 GMT

Q1. Is it posible to measure Vreg or Bootstrap voltage?

Q2. Is there any references for temperature calibration?

Q3. In freemaster, scaling values are different each other when convert from frac16 to real value, reason why?

(e.g. Actual Speed RPM is converted with 17895, DCBusCurrentZC is converted with 32767, DC Bus voltage is converted with 13653)

Q4. the values in ADC Result list array are over 2^12, reason why?

Re: Several Questions for S12ZVM

DPB — Thu, 23 Oct 2014 08:31:31 GMT

Hello

Q1 reply:

ADC0 internal_4 channel is mapped to the BATS monitor, which is a 1:9 scaled down VSUP.

To measure this it is also necessary to set BSUAE and BSUSE in the BATE register.

ADC0 internal_1 can also be mapped to the VREG bandgap voltage.

ADC0 and ADC1 channels internal_3 are mapped to the 1:5 scaled GDU DC link voltage (HD).

The bootstrap voltage cannot be directly measured on chip.

Q2 reply:

Calibration must be done by the user

The application note AN3624 which was written for S12X still basically applies for S12Z.

The temperature sensors are mapped to the ADC channels as shown in RM Table 1-7 and 1-8.

The temperature slope is given in Table B-1.

Q3: I am not a freemaster expert, so can't comment.

Q4 reply:

By default the 12-bit values are left justified in a 16-bit field.

They can be configured as right-justified by the DJM bit.