US 4,785,414 AGranted

Computer system with automatic range checking and conversion of data words

OwnerGoran A. H. Hemdalinventor

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Abstract

The disclosure relates to a computer system having a central processing unit and a main memory for storage of information in binary form. A master control unit is provided for performing individual and selected range checking and range conversion by reading of information from an internal memory of the master controlled unit which contains a data Descriptor Table with a table entry for each individually accessible data element in the main memory with two elements of each Descriptor Table entry assigned for range check and conversion purposes. One of the elements permits one of the extreme limits of a value range of a data element in the main memory associated with a data Descriptor Table entry to be determined and the second element allows the number of values in the value range of the associated data element to be determined. There is also provided a set of arithmetic circuits interposed in the data path to and from the main memory to be utilized for each read of write of information to and from the main memory. Thus the arithmetic circuits receive their input from the main memory and from the data Descriptor Table entry for a data element and deliver their output to the central processor unit by reading of information from a main memory and also receive input from the central processor unit and the Data Descriptor Table entry for the data element and deliver a corresponding output to the main memory. The master control unit has means for generating an interrupt signal to the central processor unit in the case of an out of range value being detected.

Claims10

Dependent claims

A computer system with automatic range checking and conversion of data words, comprising:

a central processing unit;
main memory means for storing information, in binary form;
and
master control means interposed between said main memory means and said central processing unit for automatically normalizing data words having logical values from said central processing unit to values within predetermined ranges and transmitting the normalized data words to said main memory means for storage therein and for converting normalized data words from said main memory means to logical values utilizable by said central processing unit and transmitting the converted data words to said central processing unit, said master control means comprising:
secondary memory means including a data descriptor table for storing for each data storage address in said main memory means a first entry specifying a predetermined number of possible consecutive values allowable for a data word stored in such data storage address and a second entry specifying a limiting value of said predetermined number of possible consecutive values;
arithmetic circuit means operatively connected to said secondary memory means, said main memory means and said central processing unit for algebraically combining a data word from any selected data storage address in said main memory means with the limiting value corresponding to said selected data storage address and forwarding a resulting converted data word to said central processing unit and for receiving an incoming data word from said central processing unit to be stored in a given data storage address in said main memory means, algebraically combining said incoming data word with the limiting value corresponding to said given data storage address and operating on said incoming data word with the predetermined number of possible consecutive values corresponding to said given data storage address to obtain a normalized data word and transmitting the resulting normalized data word to said main memory means;
and
checking means operatively connected to said central processing unit for checking values of data words to be transmitted to the memory or processor against predetermined data ranges and transmitting to said central processing unit an interrupting signal upon detection of an out-of-range value.

5 more elements

A computer system with automatic range checking and conversion of data words, comprising:

a central processing unit;
main memory means for storing information in binary form;
and
master control means interposed between said main memory means and at least a portion of said central processing unit for automatically normalizing data words having logical values from said portion of said central processing unit to values within predetermined ranges and transmitting the normalized data words to said main memory means for storage therein and for converting normalized data words from said main memory means to logial values utilizable by said central processing unit and transmitting the converted data words to said portion of said central processing unit, said master control means comprising:
secondary memory means including a data descriptor table for storing for each data storage address in said main memory means a first entry specifying a predetermined number of possible consecutive values allowable for a data word stored in such data storage address and a second entry specifying a limiting value of said predetermined number of possible consecutive values;
arithmetic circuit means operatively connected to said secondary memory means, said main memory means and said portion of said central processing unit for algebraically combining a data word from any selected data storage address in said main memory means with the limiting value corresponding to said selected data storage address and forwarding a resulting converted data word to said portion of said central processing unit and for receiving an incoming data word from said portion of said central processing unit to be stored in a given data storage address in said main memory means, algebraically combining said incoming data word with the limiting value corresponding to said given data storage address and operating on said incoming data word with the predetermined number of possible consecutive values corresponding to said given data storage address to obtain a normalized data word and transmitting the resulting normalized data word to said main memory means;
and
checking means operatively connected to said portion of said central processing unit for checking values of data words to be transmitted to the memory or processor against predetermined data ranges and transmitting to said portion of said central processing unit an interrupt signal upon detection of an out-of-range value.

5 more elements

Dependencies are inferred from the claim text.