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Answers Database
Programmers: Data I/O: Checksums on Data I/O programmers may not match when doing a "load" and doing a "read"
Record #930
Product Family: Hardware Urgency: Standard General Description: Checksums on Data I/O programmers may not match when doing a "load" and doing a "read". "Load" operations are done prior to programming a part, while "read" can be done at any time before or after the part is programmed. Solution 1: This is because the Data I/O checksum algorithms for "load" and "read" operations differ. When calculating the checksum after a "load", Data I/O includes the manufacturer's ID in its calculation. The manufacturer's ID is also included in the calculation when the checksum is calculated at the end of the programming process. However, Data I/O does not include this data when it calculates the checksum after a "read". This applies to our 1700 families and 7000 families devices as well. This may pose a problem for some customers who want to be able to get the same checksum for both operations. There is no workaround for this, but the user may take some level of comfort in knowing that they should see the same checksum within the confines of what may be considered a single "operation"--that is, the checksum they get when they load a programming file to program a device, and the checksum they see at the end of programming should match, and the checksum they get when they read a device as a master, and when they immediately program a part using the same master, should also match. For details on the actual checksum calculation algorithms used by a specific manufacturer (e.g., Data I/O), contact that manufacturer directly. Note that this information may be proprietary in nature. End of Record #930 - Last Modified: 07/30/99 13:56 |
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