Dynamically Reconfigurable N-Way Microsequencer
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
A dual-role microcode sequencer supports high performance N-way microsequencing operations (IBM System/370-type branch address generation techniques) as well as more traditional (AMD 2910) sequencing control over structured microcode. The sequencer's N-way branching is dynamic with respect to the degree of parallel branching for a control store address. The chip can be reconfigured to support 2-way, 4-way, ... up to 256-way branching on a 14-bit control store address. (Image Omitted) Sixteen microsequencing operations are supported, including: Next Sequential Control Store Address, N-Way Branch, N-Way Call and N-Way Return (including several submodes), Conditional Branch, Conditional Call and Conditional Return, and Loop Control. An on-chip stack provides microroutine nesting up to 8 levels deep.