RapidIO II MegaCore Function User Guide Does Not Explain How to Write to OUTSTANDING_ACKID Field of Port 0 Local AckId CSR - RapidIO II MegaCore Function User Guide Does Not Explain How to Write to OUTSTANDING_ACKID Field of Port 0 Local AckId CSR Description The RapidIO II MegaCore Function User Guide states that user software can write to the OUTSTANDING_ACKID field of the Port 0 Local AckID CSR (offset 0x148). However, this register field is read-only. Instead, if user software writes to the OUTBOUND_ACKID field of this register, the new value appears in both the OUTBOUND_ACKID field and in the OUTSTANDING_ACKID field. The user guide does not explain that writing to the OUTBOUND_ACKID field of the Port 0 Local AckID CSR also updates its OUTSTANDING_ACKID field. Resolution To modify the OUTSTANDING_ACKID field of the Port 0 Local AckID CSR, you must write to the OUTBOUND_ACKID field of this register. You cannot write directly to the OUTSTANDING_ACKID field. This issue is fixed in version 14.0 of the RapidIO II MegaCore Function User Guide . Custom Fields values: ['novalue'] Troubleshooting novalue True ['novalue'] ['FPGA Dev Tools Quartus II Software'] 14.0 12.1 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']