I looked a the two errata sheets on the x88x page. I see errata about peripherals, interrupts. But I did not see any errata for the XC800 core. However according to SDCC_XC800.mht from DAvE-Bench, section 3, "Silicon bug workarounds", there are two ("Hardware Cache Miss" and "Mov DIR, DIR (address of DIR >= 0x80)". I'd like to know more about them than what is mentioned in SDCC_XC800.mht.