Occasional Contributor
Regular ContributorHi TN-Notebooks,
The behavior you observed, being unable to read out or verify the contents of the CFM (Configuration Flash Memory), is expected and by design. For security reasons, the CFM, which holds the device’s logic, cannot be read back or cloned using Quartus or any other supported tools, even if the memory is empty. This applies to all MAX II and MAX V devices and is confirmed by Altera/Intel documentation.
Only the UFM (User Flash Memory) area is accessible for read and write operations via JTAG or the logic interface. If you need to duplicate or back up device logic, the original programming file (POF) is required. Without it, the logic configuration cannot be extracted or cloned from the device.
This behavior is normal and expected, not a bug or hardware issue.
For further reference, please see the "Design Security" and "User Flash Memory Programming" sections of the MAX V Device Handbook.
If you have any further questions, please let us know.
Regards,
Fakhrul
Occasional ContributorHallo Fakhrul
thank you for your response.
The Design Security say that it is possible to protect the CFM if you set the Security BIT -
However, conversely the wording of the text of the Handbook also states that it is possible to read the CFM if the security bit is not set.
During the test on the development board, the chip was deleted (as described in the Design Security) and no security bit was set.
copy of the text from the manual:
Design Security All MAXV devices contain a programmable security bit that controls access to the data programmed into the CFM block. If this bit is programmed, you cannot copy or retrieve the design programming information stored in the CFM block. This feature provides a high-level design security because programmed data within flash memory cells is invisible. You can only reset the security bit that controls this function and other programmed data if the device is erased. The SRAM is also invisible and cannot be accessed regardless of the security bit setting. The security bit does not protect the UFM block data, and the UFM is accessible through JTAG or logic array connections
and
User Flash Memory Programming The QuartusII software (with the use of .pof, .jam, or .jbc files) supports programming of the UFM block independent of the logic array design pattern stored in the CFM block. This allows updating or reading UFM contents through ISP without altering the current logic array design, or vice versa. By default, these programming files and methods program the entire flash memory contents, which includes the CFM block and UFM contents. The stand-alone embedded Jam STAPL Player and Jam Byte-Code Player provide action commands for programming or reading the entire flash memory (UFM and CFM together) or each independently.
This contradicts your statement
According to this information, you should be able to read and copy the CFM
