Having done the mapping for the G400 HDR, I have some updates for the pin mapping provided in the G400 Brochure.
PA10 - Mislabeled as ‘COM2 DTXD’ it should be 'COM1 DTXD’
PC21 - Not labeled, should be PWM 3
This is not necessarily comprehensive, these are just the items I picked-up when I was double checking the socket mappings.
@ taylorza
Thanks for the heads up. We have just replaced the older brochure with the newer one. This one reflects the changes of which you speak.
Thank you for the positive feedback. 
@ Aron - That is great, thank you.
I noticed the new brochure still indicates that there is 1 analog out and under features it indicates that the module has a DAC.
I’m not sure about PA14 (SPI0 NPCS0). The brochure says pin 122, the ChipwokX vs G400 indicates 122 is PD7. It looks like PD7. Does PA14 come off the module or is it dedicated to the dataflash?
@ taylorza
Sorry about any confusion. This MPU does not have a Digital to Analog converter. We will update the brochure as soon as possible.
@ dfarrell
You may have an older version of the brochure that may list the pins incorrectly. PA14 (SPI0 NPCS0) is correct. Pin 122 is indeed PD7 as you have indicated.