Software Verification of Microcode Transfer Using Cyclic Redundancy Code Algorithm
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
A technique is described whereby microcode information is verified by using cyclic redundancy check (CRC) code methods during data movement from ROM to control RAM of a computer processor. Described is an expansion of CRC implementation to cover data sixteen bits long and to perform the CRC operation in either hardware or software. In addition, the concept enables a CRC to be performed at processor power-up time so that the microcode can be checked by means of the CRC algorithm during the transfer from ROM to control RAM. (Image Omitted) CRC algorithms have been used for many years [*] for detecting errors in the transfer of cyclic code, particularly when using communications protocol. The CRC code is generally stored in ROM and verified by the hardware.