One cycle processor for real time processing

• US 5,752,065 A
• Filed: 06/07/1995
• Issued: 05/12/1998
• Est. Priority Date: 11/29/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Staiger, Dieter E.
• Primary Examiner(s): Coleman, Eric
• Application Number:
  US08/477,207
• Time in Patent Office: 1,070 Days
• Field of Search: 395/375, 395/800, 395/800.01, 395/800.4, 395/800.19, 395/800.25, 395/800.43
• US Class Current: 712/1
• CPC Class Codes: G06F 9/223 Execution means for microinstructions irrespective of the microinstruction function, e.g. decoding of microinstructions and nanoinstructions; timing of microinstructions; programmable logic arrays; delays and fan-out problems
• CPC Class Codes: G06F 9/265 by address selection on input of storage

Abstract

A processing unit (100) with a processor (110) for processing an operation code and a method for processing the operation code in the processing unit (100). The processor (110) comprises an operation code control unit (200) for receiving and processing the operation code in a boolean circuit (230) and generating a logical result thereof, and a next address control unit (210) comprising a multiplexing unit (250) with a plurality of input lines (A-D) selectable by the multiplexing unit (250) by means of the logical result of the boolean circuit (230). The processor (110) is triggerable by a trigger signal (CLOCK) and each operation code is processable by the processor (110) between successive trigger signals (CLOCK). When the trigger signal appears, the processor (110) issues a signal comprising an address of the operation code to be processed to the control memory (129) and/or a user data memory (140). The operation code corresponding to that address is loaded from the control memory (120) to the processor (110) and processed therein. One result of this processing is that the address of the successive operation code, which will be processed when the successive trigger signal appears. This loading and processing of operation code happens continuously in each cycle between successive trigger signals, until the end of program is reached or an interrupt signal is calling a stop routine. Each operation code is processed between successive trigger signals (or within one CLOCK cycle) allowing a predictable timing of a sequence of operation codes so that a real time condition is achievable.

Claims

1. A real time processing unit having a processor for processing an operation code, the processor comprising:

an operation code control unit for receiving and processing a first operation code in response to a first pulse of a clock and generating a logical result at an output thereof;

a memory addressable by the processor on an address line so that an operation code corresponding to the applied address is loadable by the processor, and

a multiplexing unit having a plurality of input lines selectable in response to said output of said operation code control unit, each of said plurality of input lines receiving signals representing potential next addresses in memory containing second operation codes to be processed by the processor, and the selected next address being outputed by said multiplexing unit; and

said multiplexing unit generating said selected next address before a second pulse of said clock signal is received wherein the multiplexing unit outputs said selected next address when a second pulse of said clock signal is received by the processor.

2. The processing unit according to claim 1, wherein the operation code control unit comprises a latching means receiving said clock signal so that the generated logical result is transmittable to the multiplexing unit only when a pulse of said clock signal is received.

3. The processing unit according to claim 2, wherein the operation code control unit and the multiplexing unit comprise a master-slave latch, wherein the multiplexing unit is open when the operation code control is latched, and the multiplexing unit is latched when the operation code control unit is open.

4. The processing unit according to claim 1, wherein a signal on one of said plurality of input lines indicates a potential next address that is the same as a current address.

5. The processing unit according to claim 1, wherein a signal on one of said plurality of input lines indicates a potential next address that is offset from a current address by a pre-given value.

6. The processing unit according to claim 1, wherein a given pulse from said clock signal initiates a sequential operation of said address line, said external memory, said plurality of input lines, and said multiplexer.

7. A method for processing an operation code in a real time processing unit having a processor, the method comprising the steps of:

issuing a signal comprising an address of an operation code to be processed by the processor when a first trigger signal from a clock signal with a fixed frequency is received;

loading the operation code corresponding to the address issued in the first step to the processor;

processing the loaded operation code, whereby one result of the processing is selection of an address of the successive operation code to be processed from a plurality of optional address signals, which will be processed when a successive trigger signal appears; and

modifying the data by the processor in a memory, while other user data and control data are received by the processor during the loading and processing steps.

8. The method according to claim 7, wherein the trigger signal is an asynchronous signal which appears whenever the processing of an operation code is required.

9. The method according to claim 7, wherein the operation code comprises a base function code and a sub-function code.

10. The method according to claim 9, wherein the base function code includes the operation code which is required continuously during a given processor operation;

and, wherein the sub-function code includes data required only when a specific sub-function is requested during said given processor operation.

11. The method according to claim 10, wherein the base function code comprises a control code that determines the sub-function code.

12. The method according to claims 7, wherein the step of processing the loaded operation code is determined by advancing the address of the presently processed operation code by a pre-given value when a request for a sub-function is recognized.

13. A real time processing unit, comprising:

a) an addressable memory, having operational code stored therein;

b) trigger signal input for receiving trigger signals;

c) processor means,

coupled to both the trigger signal input, and the addressable memory,

for sending, upon receiving a first trigger signal, an operational code address to the addressable memory,

for receiving, before the arrival of a next trigger signal, a corresponding operational code from the addressable memory, said operational code having a base function code and a sub-function code, and

for processing, before the arrival of the next trigger signal, the operational code to determine a next operational code address in accordance with one or both of said base function code and said sub-function code; and

d) a register for receiving the next operational code address and releasing the next operational code address from the processor means to the addressable memory upon receiving the trigger signal.

14. The processing unit according to claim 13, wherein the processor means further comprises:

a) an operation code control unit for receiving and processing the operation code, from the addressable memory, in a boolean circuit and generating a logical result therefrom, and

b) a next address control unit including;

b1) a multiplexing unit with a plurality of input lines selectable by the multiplexing unit in response to receiving the logical result, whereby the input lines represent possible combinations of operation code addresses used to select operational code stored in the addressable memory; and

b2) a register, coupled to receive the operation code address generated by the multiplexing unit, and coupled to receive the trigger signals, for sending the operations code addresses upon receiving the trigger signals.