Programmable priority branch circuit

Abstract From the Canadian patent

A special purpose circuit unit responsive to, a special BBD instruction provides for more, efficient execution of program branches required in poll and test type routines used by data processors. This unit can easily be added to almost any contemporary processing system to speed up performance of priority branch operations. It includes: a stack of registers loadable with branch addresses designating locations of branch target instructions, an input register for holding bits representing branch conditions accessible from immediate (programmable) storage, and a programmable priority encoder responsive to the BBD instruction to select an address from the stack in accordance with the position …