System and method for executing branch on bit set/clear instructions using microprogramming flow

摘要

A data processing system (10) executes a branch instruction in a straight line microcode sequence. During execution of the instruction, a control unit (56) is provided to decode the instruction to provide a plurality of control signals and to determine a data value with which to test a condition of the instruction. A constants generation circuit (222) generates a mask value in response to the plurality of control signals. An arithmetic logic unit (224) logically combines the mask value with the data value to produce a masked value. A zero detect circuit (246) subsequently tests the masked value to determine if it is equal to zero and provides a condition signal to indicate if the condition of the instruction was satisfied. If the condition of the instruction is satisfied, an offset value plus one is added to a program counter value. Otherwise, the program counter value is incremented by one.