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Portable computer having dedicated register group and peripheral controller bus between system bus and peripheral controller

  • US 5,613,135 A
  • Filed: 08/16/1993
  • Issued: 03/18/1997
  • Est. Priority Date: 09/17/1992
  • Status: Expired due to Fees
First Claim
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1. A portable computer having a CPU, a memory, a keyboard, and a system bus, the portable computer further comprising:

  • a keyboard controller connected to the CPU through the system bus, the keyboard controller having scan-out I/O ports to which scan lines are connected to transmit, to the keyboard, scan signals, and scan-in I/O ports to which return lines are connected to receive return signals from the keyboard;

    a keyboard interface bus including the scan lines and the return lines, and connecting the keyboard controller to the keyboard;

    a dedicated register group connected to the CPU through the system bus and to the keyboard controller through the scan lines of the keyboard interface bus, for temporarily storing control information exchanged between the CPU and the keyboard controller;

    wherein the keyboard controller writes a hot key data portion of key data in the dedicated register group from the scan I/O port through the keyboard interface bus, the hot key data being formed to set or change an operation mode of the portable computer; and

    wherein the keyboard controller transmits remaining key data to the CPU through the system bus.

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