Patent ID: 8135978
Filing Date: 2012-03-13
Classification: G06F

Abstract:
1. A computer system for performing a Perform Timing Facility (PTFF) instruction for steering a Time of Day (TOD) clock of the computer system for synchronizing the TOD clock with TOD clocks of other computer systems, said computer system comprising: a memory; and, a processor in communications with the computer memory, wherein the processor performs a PTFF method comprising: obtaining a function code specified in a first general register, said function code for identifying any one of a query function or a control function to be performed; obtaining, from a second general register, a memory address of a parameter block; responsive to the function code specifying a query function, storing timing information of said computer system in said parameter block according to said specified query function; responsive to the function code specifying a control function, using timing information obtained from the parameter block to perform the specified control function; and setting a condition code value indicating an outcome of the specified function, a specified control function being a steering rate control function in which said processor performs: computing a TOD offset value (d) as a function of a physical clock (Tr), a start time (s), a base offset (b), and a steering rate (r); and creating a TOD clock by arithmetically adding the TOD offset value (d) to the physical clock (Tr).