BRB Branch Record Buffer Branch Record Buffer. For more information, see op0==0b01, cache maintenance, TLB maintenance, and address translation instructions. SYS 1 1 0 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 1 0 0 1 0 BRB <brb_op>{, <Xt>} SYS #1, C7, C2, #<op2>{, <Xt>} SysOp('001','0111','0010',op2) == Sys_BRB <brb_op> Is a BRB instruction name, as listed for the BRB system instruction group, op2 <brb_op> Architectural Feature 100 IALL 101 INJ <op2> Is a 3-bit unsigned immediate, in the range 0 to 7, encoded in the "op2" field. <Xt> Is the 64-bit name of the optional general-purpose source register, defaulting to '11111', encoded in the "Rt" field.