Routing for Microprocessor Busses
OwnerAlex Hendersoninventor
Life of this patent
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Abstract
This invention provides means and methods for improving the routing and multiplexing logic of microprocessor busses and other similar high fan logic functions in FPGA and ASIC circuits. Routing of high fan-in signals is simplified by distributing the multiplexing function. The multiplexing function is separated into an AND function in the logic block and a programmable OR function in the routing block. Programming bits control which signals are ORed together in the routing elements. The AND output of a peripheral is controlled by either a distributed control circuit or by control signal(s) from a centralized control circuit.
Claims19
A method for routing signals comprising:
- use of a distributed AND function in the logic elements of a FPGA;
- and
- use of a distributed OR function in the routing components of a FPGA.
A method of implementing a fan-in function and a fan-in function's associated routing in an ASIC comprising:
- use of a distributed AND function used in the logic elements and marco cells;
- and
- use of a distributed OR function used in the routing components.
A method of assigning a routing attribute to signals that connect to a high fan function comprising:
- a) routing the signals as if they were a single signal;
- and
- b) using the signal's attribute to indicate to the place and route tools where to:
- 1) enable the OR functions in an FPGA;
- 2) insert an OR function in an ASIC;
- and
- 3) replace a repeater with an OR function.
A device for implementing a multiplexer and the multiplexer's routing in an FPGA, comprising:
- a distributed AND function used in the logic elements of the of the FPGA;
- and
- a distributed OR function used in the routing components of the FPGA.
Dependencies are inferred from the claim text.