MA2911

www.DataSheet4U.com MA2909/11 APRIL 1995 DS3577-3.4 PRELIMINARY INFORMATION MA2909/11 RADIATION HARD MICROPROGRAM SEQUENCER The MA2909/11 Microprogram Sequencer is fully compatible with the industry standard 2909A and 2911A components, and forms part of the GPS 2900 Series of devices. The series offers a building block approach to microcomputer and controller design, with each device in the range being expandable to permit efficient emulation of any microcode machine. The devices have tristate outputs and have an internal address register, with all internal registers changing state on LOW to HIGH clock transition. The 4-bit slice can cascade to any number of microwords. Branch input for N-way branches is supported. Additional features include: I 4-bit cascadable microprogram counter. I 4 x 4 file with stack counter supporting nesting microsubroutines. I Zero input for returning to the zero microcode word. I Individual OR input for each bit for branching to higher microinstructions (2909 only). The 2909 is a 4-bit wide address controller intended for sequencing through a series of microinstructions contained in a ROM or PROM. Two 2909s may be interconnected to generate an 8-bit address (256 words), and three may be used to generate a 12-bit address (4K words). The 2909 can select an address from any of four sources: 1) A set of external direct inputs (D); 2) External data from the R inputs, stored in an internal register; 3) A four-word push/pop stack; or 4) A program count...