×

Slave processor with clock controlled by internal ROM & master processor

  • US 4,467,412 A
  • Filed: 05/18/1981
  • Issued: 08/21/1984
  • Est. Priority Date: 05/18/1981
  • Status: Expired due to Fees
First Claim
Patent Images

1. In a system containing a host processor with a host address bus, a host data bus, and a system clock line, a slave processor and slave address bus comprising:

  • memory means for storing microinstructions and providing stored microinstructions on a memory output bus in response to addresses presented on said slave address bus, said memory means being a read only memory;

    an arithmetic logic unit coupled to at least a portion of said memory output bus, said arithmetic logic unit being adapted to perform arithmetic and logic operations in response to microinstructions provided by said memory means on said memory output bus, said arithmetic logic unit also being coupled to a slave clock line for receiving clock signals;

    a sequencer coupled to said slave address bus, said sequencer providing addresses on said slave address bus;

    a decoder coupled to said host address bus, said decoder providing a start signal in response to the presence of a predetermined address on said host address bus;

    a clock control circuit coupled to said system clock line, said slave clock line, said decoder and at least one output line from said memory means, said clock control circuit sending clock signals on said slave clock line in response to clock signals on said system clock line, terminating the sending of clock signals on said slave clock line in response to the presence of a predetermined condition on said output line, and resuming the sending of clock signals on said slave clock signal line in response to said start signal;

    a mapping ROM coupled to said host address bus, said mapping ROM providing an address on a mapping ROM output bus in response to addresses on said host address bus;

    a multiplexer coupled to said mapping ROM output bus, said multiplexer providing an output on a multiplexer output bus in response to data on said mapping ROM output bus; and

    a load control circuit coupled to said sequencer and said start signal output line, said load control circuit causing the loading by the sequencer of the data on said multiplexer output bus in response to a start signal on said start signal output line.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×