S: automotime part, mask set specific – usually mask is not presented as on this device (0N75C) but as a code, for example F0, in the part number. Explained also bellow.
9 FLASH ROM ( 3 OTPROM – I think not applicable for S12G device)
G48 – device family and Flash EEPROM size
M: -40°C to 125°C
0N75 …. Mask set revision =0; mask set number = 75C – corresponding errata list is presented on the web
LF – Package option - 48 LQFP
CTWNRK – internal tracking (confidential code). Hidden also for support. You should have internal contact to production to explain it.
The data sheet presents full option (see picture bellow or Ordering and Shipping Information in the data sheet). The difference to your device is that mask set is hidden in the code F0. If there is such a marking used the mask and revision is not printed on the package.