Multiport memory bypass under software control
First Claim
1. A data processing device structured for operation under control of a sequence of instructions forming a program, the device including:
- (a) storage means including a plurality of storage locations each having their own address and having at least first and second data ports for providing parallel access to storage locations at different addresses in accordance with respective first and second addresses encoded in a first type of program instruction,(b) said sequence of instructions including a second type of program instruction which includes an explicitly encoded bypass signal to simulate parallel access of both data ports to a storage location at the same address,(c) bypass means responsive to said bypass signal upon execution of said second type of program instruction for connecting the second data port to the first data port to avoid simultaneous parallel access by both data ports to the storage location at the same address.
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Accused Products
Abstract
A program-controlled processing device includes a multiport memory circuit providing a plurality of storage locations. First and second data ports of the memory circuit provide parallel access to different locations in accordance with first and second addresses encoded in the program instructions. Bypass means is provided for coupling the second data port to the first data port to simulate parallel access to the same location when desired. The bypass means is controlled directly by the program instructions, by means of a separate bypass control field or by a special value of one of the two addresses. There is thus no need for a run-time comparison of addresses before each memory access, leading to a faster operation of the memory circuit.
44 Citations
19 Claims
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1. A data processing device structured for operation under control of a sequence of instructions forming a program, the device including:
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(a) storage means including a plurality of storage locations each having their own address and having at least first and second data ports for providing parallel access to storage locations at different addresses in accordance with respective first and second addresses encoded in a first type of program instruction, (b) said sequence of instructions including a second type of program instruction which includes an explicitly encoded bypass signal to simulate parallel access of both data ports to a storage location at the same address, (c) bypass means responsive to said bypass signal upon execution of said second type of program instruction for connecting the second data port to the first data port to avoid simultaneous parallel access by both data ports to the storage location at the same address. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A multiport memory circuit comprising:
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(a) an array of data storage locations associated with respective different address values, (b) first and second data ports for writing data to and reading data from said first and second data ports, (c) address decoding means for receiving respective first and second address values and for enabling parallel access via the first and second data ports to respective data storage locations in accordance with received address values, (d) bypass means for connected the second data port to the first data port to avoid accessing any data storage locations in response to the decoding means receiving a predetermined value of at least one of the received addresses, said predetermined value being different from the address values associated with any of the data storage locations in the array and not being capable of addressing any of such data storage locations, so as to simulate parallel access of both data ports to a storage location at the same address. - View Dependent Claims (18, 19)
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Specification