Browse Prior Art Database

Logging and Initializing Microcontroller Facilities

IP.com Disclosure Number: IPCOM000114763D
Original Publication Date: 1995-Jan-01
Included in the Prior Art Database: 2005-Mar-29
Document File: 4 page(s) / 115K

Publishing Venue

IBM

Related People

Bubb, CE: AUTHOR [+2]

Abstract

Disclosed is a method of logging and initializing the various facilities associated with a microcontroller. These facilities include the microprocessor's control registers, working registers, local storage, and memory mapped IO registers. All of the facilities are checked by parity, and the microcontroller initializes the facilities and their parity fields as it enables the parity checkers. The microcontroller uses alternate memory mapped addresses to read many of the facilities. These alternate addresses inhibit possible bad parity from propagating to the microprocessor's internal facilities.

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This is the abbreviated version, containing approximately 47% of the total text.

Logging and Initializing Microcontroller Facilities

      Disclosed is a method of logging and initializing the various
facilities associated with a microcontroller.  These facilities
include the microprocessor's control registers, working registers,
local storage, and memory mapped IO registers.  All of the facilities
are checked by parity, and the microcontroller initializes the
facilities and their parity fields as it enables the parity checkers.
The microcontroller uses alternate memory mapped addresses to read
many of the facilities.  These alternate addresses inhibit possible
bad parity from propagating to the microprocessor's internal
facilities.
  ORDER    HARDWARE AREA           LOGGING METHOD       RESET
    1    Primitive Instruction    Shadow             Power On/
           Execution                Registers          Recovery
            - Main Store                               Reset
            - Control Store
            - LOAD and STORE
            - Error Control
    2    General Purpose          STORE into LOCAL   Microcode
           Registers                STORE SAVE
                                    AREA
    3    Microcontroller          LOAD into GPR's    Microcode
           Control Registers        using LOGGING
                                    IMAGE and save
                                    in LOCAL STORE
    4    Microcontroller          COPY to Main       Microcode
           Local Store              STORE.  COPY
                                    PARITY as DATA
    5    IO Units                 LOAD into GPR's    Microcode
            - memory mapped         using LOGGING
                                    IMAGE and save
                                    in LOCAL STORE

              Figure 1    LOGGING and RESET FUNCTIONS

      In computer systems using microcontrollers with error detection
logic, several methods of logging the state of the hardware and
resetting the hardware after an error has been detected have been
employed.  One method uses a service processor to read and initialize
the hardware facilities either through direct access to the registers
or through scan paths.  Since this method is often very slow, another
method has been to allow the microcontroller itself to log its
various
facilities while disabling its own error checking.  This method adds
considerable complexity to the design since some error detection must
be enabled when calculat...