Diagnostic Programming Using Special Function Register
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
The addition of a Special Function Register to a processor storage card enables direct access to either error correction code and redundant bit arrays or to uncorrected data for more efficient diagnostic storage operations. This technique avoids limited data transfer, slow execution time and reading prior correction bits typically experienced with the usual Processor Bus Operations (PBO). A Special Function Register on the storage card comprises four bits in each of two data flow chips and places the logic in special modes during diagnostic procedures. When performing diagnostics of the checkbit and redundant bit correction arrays, the Special Function Register is set to a value enabling the mode of always transferring data directly into and out of the correction arrays.