Restoration Of Arrays Containing Bad Parity
Original Publication Date: 1979-Oct-01
Included in the Prior Art Database: 2005-Feb-20
Certain processors use instruction retry as the system retry procedure. This type of retry may require that all architected items be restored to their original value at the beginning of the instruction. For example, the items restored by the retry instruction processing unit (IPU) microcode could be the general purpose and floating registers, located in a local store, as well as any modified storage data which is located in a cache in the system. A problem can arise if the local store or the cache contain data having bad parity, since these arrays must be sourced before any destination.