Hi Ray,
I am not aware of any specific document describing Timer's Output Compare functionality except device reference manual.
The Output Compare functionality is provided in Functional Description of the module having that feature. Specifically in S12XE ref.manual v1.25, the chapter is 22.4.3 Output Compare.
At the link below you can find couple of SW example demonstrating functionality of ECT and PIT modules on S12XE:
S12X Examples Pack
Further you can go and check lama's unofficial examples link provided in above document page.
If you would like SW example for TIM module, then you can re-use the code from the SW example made for S12G device. The TIM module is very much the same on S12XE and S12G.
https://community.nxp.com/docs/DOC-93792
I hope the information helps.
Regards,
iggi