Why do reads from the last byte address on my EPCQ device fail? - Why do reads from the last byte address on my EPCQ device fail? Description Due to a problem in the Altera Nios® II HAL driver for the Altera EPCQ IP, you may be not be able to read the last byte of EPCQ devices using the following command: alt_read_flash (fd, 0xFFFFFF, ch, 1); where (0xFFFFFF is last byte address of EPCQ) The function will error with a return value off -22 when reading last byte of EPCQ. (If the command is successful, the return value is 0). Resolution The Nios II HAL driver for the code of the EPCQ driver has a variable called end_address. This variable was incorrectly assumed non-inclusive. To fix this problem: In the Quartus® Prime software 15.0 and above change line 730, In Quartus Prime software 14.1 and below change line 611 as follows to remove the = in the compare: end_address > epcq_flash_info->data This problem is scheduled to be fixed in a future release of the Quartus software. Custom Fields values: ['novalue'] Troubleshooting FB: 381619; False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] 17.0 14.1 ['Arria® V ST FPGA', 'Arria® V SX FPGA', 'Cyclone® V SE FPGA', 'Cyclone® V ST FPGA', 'Cyclone® V SX FPGA', 'Arria® 10 SX FPGA'] ['Embedded Dev Tools SoC Suite'] ['novalue'] ['novalue']