Andrew,
Are you using EZSDK 5.05.02.00 / PSP 04.04.00.01?
[quote user="Andrew Elder"]However, when I change the MULT_MSG_CAP to 1[/quote]
As this bit field MSI_CAP[19:17] MULT_MSG_CAP is read-only, how exactly you are changing it from 0x0 to 0x1?
[quote user="Andrew Elder"]I have a DM814x showing up correctly in Windows[/quote]
Do you mean that you are using DM814x as PCIe EP and x86 PC Windows as RC?
Make sure you are aligned with the below user guides:
http://processors.wiki.ti.com/index.php/TI81XX_PSP_PCI_Express_Endpoint_Driver_User_Guide
http://processors.wiki.ti.com/index.php/TI81XX_PSP_PCI_Express_Endpoint_Boot_Driver_User_Guide
http://processors.wiki.ti.com/index.php/TI81XX_PCIe_FAQs
Regards,
Pavel