Logic circuit and method for evading hot spot on integrated circuit

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to alleviating the problem of heat generation due to power consumption, and more particularly to logical steering of functions or instructions for avoiding local heat generation areas or hot spots on integrated circuits.

【0002】

[Conventional technology]

Limiting power consumption is one of the main goals when designing microprocessors. The power consumption of microprocessors is increasing significantly with the advent of new semiconductor technologies, increasing density and complexity, and increasing clock speeds.

【0003】

Many current microprocessor designs force idling of specific parts (or functional units) of the microprocessor chip to prevent the potential for catastrophic destruction if locally heated. There is a problem of being struck. When such problems occur, the overall throughput of the microprocessor chip is significantly reduced. This is because the microprocessor must wait to perform the operation of the idle functional unit until the effects of local heat generation are no longer a threat.

【0004】

The overall throughput of the microprocessor chip is measured in units of "SPEC" marks. The SPEC mark for a particular microprocessor is determined by running multiple standard programs and assessing the performance of the microprocessor, resulting in a given microprocessor throughput. As you can see, shutting down functional units due to local heat problems reduces the likelihood that these units can be used to perform calculations, which reduces microprocessor throughput.

【0005】

Traditional attempts to combat local heat generation have focused on arranging functional units in integrated circuits and powering off (disable) units that are not needed for a given operation. Strategic placement of units can alleviate some local heat problems, but increases chip density and requires functional units to operate relatively non-stop to perform computational enhancement programs and operations. So the placement and layout on the chip has little or no effect. A typical embodiment for powering off a unit includes a central control unit that disables unwanted functional units based on incoming / outgoing commands or actions.

【0006】

Other attempts to improve SPEC throughput have focused on adding multiple functional units. For example, the fixed-point (or floating-point) calculation SPEC mark can be improved by adding a second fixed-point functional unit to the microprocessor design. However, in the case of multiple units with the same characteristics, no consideration is given to which functional unit is blocked or disabled. In some attempts, each functional unit was simply used alternately. Even with such techniques, the problem of local heat generation in such functional units remains a problem, as there is a lack of consideration for the actual power consumption (or activity) within the neighborhood (region) of each functional unit. It remains as it is.

【0007】

[Problems to be Solved by the Invention]

Therefore, there is a need for equipment and methods to reduce local heat problems associated with functional units in microprocessors. In addition, there is a need for devices and methods that provide information about power consumption in or around a given functional unit. In addition, to reduce the potential for catastrophic failure (s) due to overheating, to increase the reliability of the microprocessor chip, and to reduce the overall average power consumption of the microprocessor chip, the micro Devices and methods for logical steering of processor instructions (or operations, functions) are required. Therefore, logical steering of instructions to different functional units within separate neighborhoods is required to reduce the effects of local heat generation and increase microprocessor throughput.

【0008】

[Means for solving problems]

The present invention provides circuits for distributing instructions to one of a plurality of functional circuits, each positioned within various regions of an integrated circuit. This circuit includes a first functional circuit positioned within a first region of the integrated circuit and a second functional circuit positioned within a second region of the integrated circuit. The first functional unit and the second functional unit can perform almost the same function in response to an instruction. This circuit measures or predicts the power consumption in the first region of the integrated circuit, and further adds a first circuit for generating a first signal related to the measurement or predicted power consumption in the first region. Including. The second circuit is provided to measure or predict the power consumption in the second region of the integrated circuit and generate a second signal associated with the measurement or predicted power consumption in the second region. .. The first signal and the second signal are processed, and when the power consumption in the second region exceeds a predetermined amount, the power consumption in the first functional circuit or in the first region is determined. When the amount is exceeded, a command is routed to the second functional circuit to execute the operation.

【0009】

INDUSTRIAL APPLICABILITY The present invention provides a method for reducing power-related local heat generation on an integrated circuit. A first functional unit is provided on the integrated circuit in the first region of the integrated circuit, and a second functional unit is provided on the integrated circuit in the second region of the integrated circuit. The first functional unit and the second functional unit perform almost the same function in response to an instruction. In this method, a step of determining whether or not a local heat generation problem exists in the first region of the integrated circuit and a step of determining whether or not a local heat generation problem exists in the second region of the integrated circuit are performed. Including. Depending on whether a local fever problem is detected, one of the functional units not located within the region with the local fever problem, or the local fever problem exists in both the first and second regions. If so, dispatch or route instructions to one of all functional units.

【0010】

For a more complete understanding of the present invention and its advantages, reference is made to the following description along with the accompanying drawings.

【0011】

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the accompanying drawings, the same reference characters indicate the same or similar parts throughout the attached drawings.

【0012】

Next, referring to FIG. 1, the figure shows a device 100 for logically steering instructions to avoid "hot spots" on the integrated circuit 198. The apparatus 100 includes a first region 102 (or neighborhood region) and a second region 104 (or neighborhood region) on the integrated circuit 198. Within the first region 102 are a first functional unit 106, a power prediction circuit 110, and other functional units or circuits 150, 151, 152, 153, 154, 155. Other functional units or circuits 150, 151, 152, 153, 154, 155 are of the type (s) commonly found in microprocessors (in integrated circuit 198) and perform a given function. (That is, units such as floating-point / fixed-point arithmetic logic units (ALUs), registers, bus interfaces, cache memory, second smaller processors, etc.). The first functional unit 106 may be of any type as long as it is a circuit that executes a function in response to an instruction.

【0013】

Within the second region 104 are a second functional unit 108, a power prediction circuit 112, and other functional units or circuits 156, 157, 158, 159, 160. Other functional units or circuits 156, 157, 158, 159, 160 are of the type commonly found in microprocessors and perform a given function (ie, floating point / fixed point arithmetic unit (ALU)). Units such as registers, bus interfaces, cache memory, second smaller processor, etc.). As you can see, the functional units 150, 151, 152, 153, 154, 155 in the first region 102 are the same as or similar to the functional units 156, 157, 158, 159, 160 in the second region 104. Can be

【0014】

The first functional circuit or unit 106 and the second functional circuit or unit 108 do not have to be structurally the same. However, the first functional unit 106 and the second functional unit 108 perform substantially the same function or operation in response to an instruction. For example, if the first functional unit 106 is an ALU, then the second functional unit 108 should also be an ALU, and if the first functional unit 106 is an on-chip cache memory, then the second functional unit The 108 should also be an on-chip cache memory, and so on.

【0015】

The power prediction circuit 110 located in the first region 102 measures or predicts the power consumption in the first region 102. Similarly, the power prediction circuit 112 located in the second region 104 measures or predicts the power consumption in the second region 104. From the measured or predicted power (eg, power consumption) in each region 102, 104, the power prediction circuits 110, 112 also determine if the power in each region 102, 104 exceeds a predetermined amount or value. To do. When the power in the first region 102 exceeds a predetermined amount, there is a local heat generation problem in the first region 102, and this state is transmitted by the signal line 118. Similarly, when the power in the second region 104 exceeds a predetermined amount, there is a local heat generation problem in the second region 104, and this state is transmitted by the signal line 122. As you can see, measuring (or predicting) power consumption can be performed by one of a variety of methods known to those of skill in the art. For example, an ammeter (with or without an A / D converter) is used to sense the current of the power line to that area, the temperature in that area, and the actions taken by the circuits in that area. Power measurements can be made by counting clock cycles or counting instructions.

【0016】

The device 100 also includes a dispatch unit 114 having a power cutoff control unit 116. The power cutoff control unit 116 receives information regarding the amount of power (power consumption) in the first area 102 and the second area 104 via the signal lines 118 and 122. If local heat problems are apparent in some or all of the regions (or neighborhoods) 102, 104, dispatch unit 114 sends instructions to the appropriate functional units 106, 108 to be executed by the designated functional unit. Those skilled in the art will avoid power-related "hot spots" on the integrated circuit 198 and will be located in multiple functional units of the same type (ie, in different regions) in response to power consumption within each region. You will find that dispatch unit 114 performs "logical steering" to distribute or dispatch instructions (s) to one of them (performing the same or similar function). As you can see, integrated circuit 198 includes three or more regions, each region that can contain functional units capable of performing approximately the same function or operation in response to an instruction.

【0017】

For example, assume that the measured or predicted power consumption in the first region 102 exceeds a predetermined amount. Therefore, a local heat generation problem is detected in the first region 102, and this information is relayed to the power cutoff control unit 116 via the signal line 118. Therefore, the power prediction circuit 110 notifies the dispatch unit 114 that a local heat generation problem has occurred in the first region 102. Further assume that the next pending instruction is scheduled for the first functional unit 106 in the first region 102 and the other region 104 has a corresponding duplicate functional unit 108 (duplicate). Means that the other functional unit is formally or functionally identical, at least for that particular action associated with the instruction). The dispatch unit 114 then sends an instruction to the second functional unit 108 to perform the required operation, enabling the second functional unit 108 via the signal line 124. Moreover, the dispatch unit 114 disables the first functional unit 106 by the signal line 120, thereby putting the first functional unit 106 into low power mode. This reduces the power consumption in the first region 102 and also reduces both the local heat generation problem in the first region 102 and the possibility of catastrophic failure due to overheating. When the local heat generation problem in the first region 102 is no longer a problem, or the first functional unit 106 is needed for operation, the dispatch unit 114 sends the first functional unit 106 to receive the next instruction. Make it available. As you can see, some applications force the functional unit 106 to operate to achieve a given system throughput or other benefits, thereby ignoring local heat problems detected within that region. There is also something to do.

【0018】

Next, referring to FIG. 2, the figure shows a detailed view of the power prediction circuits 110 and 112. The power prediction circuits 110 and 112 measure or predict the power consumption in the regions 102 and 104, respectively, and determine when a local heat generation problem exists in any region. Each power prediction circuit 110, 112 includes a power measurement circuit 200 that predicts or measures the power in its respective region. In one embodiment, the power consumption in each region is measured or predicted for each functional unit in each region. Therefore, the power measurement circuit 200 in the first region 102 is each of the individual functional units (first functional unit 106 and units A, B, C, D, E, F) in the first region 102. Measure or predict power consumption. Similarly, the power measurement circuit 200 in the second region 104 is the power of each of the individual functional units (the second functional unit 108 and the units U, V, W, X, Y) in the second region 104. Measure or predict consumption.

【0019】

Each power prediction circuit 110, 112 further includes an encoder 202 that sums the measurements or predicted power consumption of the individual functional units within that region. Encoder 202 can be designed to weight measured or predicted power from individual functional units. Weights are assigned based on priority, usage level, and so on. Further, a functional unit having a high density or a functional unit requiring a large amount of power during use may need to be increased in weight. As you can see, the weighting of the collected power information can be arbitrary and is not essential.

【0020】

The power measurement circuit 200 of another embodiment measures or predicts power consumption as the sum of the respective regions. For example, if the integrated circuit 198 is constructed so that a single voltage supply line (or multiple identifiable power lines) powers only each region, then at one (or more) points. Power is measured. Therefore, in contrast to measuring the power for each functional unit in the region and summing the measurements, this reduces the amount of circuitry required to measure the power in the region. Can be done.

【0021】

Those skilled in the art will appreciate that multiple means or circuits can be used to determine, measure, or predict power consumption within each region of an integrated circuit. Whether the power measurement circuit 200 measures the current of all or each power line to an individual functional unit (with or without an analog-to-digital (A / D) converter) and measures the temperature in that area. Alternatively, it can be designed to measure temperatures at various points within the region, count the number of clock cycles for each functional unit operating within the region, and count instructions. You will find that any circuit, means, or method can be used to perform the specified function of measuring or predicting power consumption within each region.

【0022】

Once the power consumption within an arbitrary region is determined, the respective power prediction circuits 110, 112 compare the measured or predicted power consumption with a predetermined quantity or value. This comparison is preferably made by the discrimination circuit 204 located within the region under measurement. Alternatively, the discrimination circuit 204 may be located closer to or within the dispatch unit 114. If the power consumption in the area exceeds a predetermined amount set for the area, a local heat generation problem has already been detected in each area. When such detection is made, the discrimination circuit 204 notifies the dispatch unit 114 by the power prediction circuit indicator signals 118 and 122, respectively (block 206). If no local heat problems are detected, the discrimination circuit 204 signals to continue normal operation (block 208).

【0023】

Next, referring to FIG. 3, a detailed view of the power cutoff control unit 116 is shown in the figure. The power cutoff control unit 116 receives the power prediction circuit indicator signals 118 and 122 from the regions 102 and 104, respectively. As you can see, n different indicator signals are generated, depending on the number of regions containing equivalent functional units. The power cutoff control unit 116 is part of the dispatch unit 114. The dispatch unit 114 can include a branch prediction logic circuit 300 and / or unit availability tracking logic circuits (not shown), which are generally present within the power cutoff control unit. The present invention adds power prediction circuit indicator signals 118, 122 to determine if and where the local heat generation problem is within a particular region. Depending on the input signal (eg, indicator signal, branch prediction signal (optional), unit availability signal (optional)), the power cutoff control unit 116 is commanded by either functional unit 106, 108 based on the operation (or functional) type. Not only to determine if it will be received, but also which areas 102, 104, i.e., the first or second functional units 106, 108, are most suitable to reduce the local overheating problem or its effects. .. Upon determining this, the dispatch unit 114 dispatches or routes an instruction to a designated desired functional unit to perform the corresponding operation or function. Meanwhile, the power cutoff control unit 116 disables the functional unit (s) in the area (s) in which the local overheating problem exists (ie, has already been detected).

【0024】

Next, referring to FIG. 4, the figure shows a basic flow diagram 400 of the method for dispatching an instruction to one of the functional units. A person skilled in the art could use the flow diagram 400 to design the circuit inside the power cutoff control unit 116. The flow chart 400 determines which functional unit receives the command based on the power consumption (local heat generation) information of the area (neighboring area). In step 402, it is determined whether or not a plurality of functional units exist to execute the requested instruction or operation. If it does not exist, dispatch unit 114 dispatches or routes the instruction to the appropriate functional unit (block 420). If there are two or more such functional units, query for the presence of local heat problems within their respective regions of each functional unit.

【0025】

In step 404, if the power prediction circuit indicator signal 118 indicates that there is no local heat generation problem in the first region 102, then the instruction to be executed is dispatched or routed to the first functional unit 106 (block 421). ). However, if a local heat problem is detected, the first functional unit 102 becomes unavailable (block 422) and the process continues. In step 406, if the power prediction circuit indicator signal 122 indicates that there is no local heat generation problem in the second region 104, then the instruction to be executed is dispatched or routed to the second functional unit 106 (block 423). ). However, if a local heat problem is detected, the second functional unit 102 becomes unusable (block 424) and the power consumption of the nth region with the functional unit (determined by the indicator signal) is inspected in step 408. The process continues until it is done. If there is no local heat generation problem in the nth region, dispatch or route the instruction to be executed to the nth functional unit (block 425). However, if the local heat generation problem also occurs in the nth region, the local heat generation problem is unavoidable (block 426), and the dispatch unit waits for a predetermined period of time before dispatching an instruction to any unit. , The steps starting with step 404 are repeated, the instruction is dispatched to one of the units, and the instruction is dispatched to a specific unit based on the default. As you can see, the flow diagram 400 is not necessary for sequentially querying the power consumption of the first region, the second region, and the nth region, but it can be configured in any way.

【0026】

According to the present invention, a microprocessor designer commands or (functions) different units in different regions in response to predicted or measured power consumption in different regions or in different regions of a microprocessor or integrated circuit. Can be logically steered.

【0027】

In summary, the following matters will be disclosed with respect to the constitution of the present invention.

【0028】

(1) In a circuit for distributing instructions to one of multiple functional units, each positioned within various regions of an integrated circuit, it is possible to perform approximately the same function in response to the instructions. Multiple functional units, where each functional unit is positioned within the corresponding region of multiple regions on the integrated circuit, and each power prediction circuit is located in the corresponding region of the plurality of regions. Multiple power prediction circuits that measure or predict power consumption within, and process each measurement or predicted power consumption of multiple regions, with predetermined measurements or predicted power consumption within the other region of the multiple regions. It is characterized by including a circuit for routing instructions to one of multiple functional units in one corresponding region of multiple regions to perform its operation when the amount of is exceeded. Circuit. (2) In the circuit, each discrimination circuit corresponds to one of a plurality of regions, receives measurement or predicted power consumption from the corresponding region, and the measurement or predicted power consumption in the corresponding region exceeds a predetermined amount. The circuit according to (1) above, characterized in that it includes a plurality of discrimination circuits that sometimes generate an indicator signal. (3) The circuit according to (2) above, wherein each discrimination circuit is structurally positioned within the corresponding region. (4) The unit power cutoff control circuit for receiving and processing the indicator signals generated by the plurality of discrimination circuits and selecting one of the plurality of regions in response to the indicator signals, and the local area. It is characterized by further including a dispatch unit for dispatching instructions to one of a plurality of functional units corresponding to one selected from a plurality of regions in order to reduce the influence of heat generation. The circuit described in (2) above. (5) The circuit according to (4) above, wherein the dispatch unit disables the remaining functional units. (6) For the circuit to receive and process measured or predicted power consumption from each of the plurality of regions to detect whether a local heat problem is present in one or more of the plurality of regions. Dispatch instructions to the unit power cutoff control circuit and one of the multiple functional units corresponding to one of the multiple regions where no local heat problems have been detected to reduce the effects of local heat generation. The circuit according to (1) above, further comprising a dispatch unit for. (7) The circuit according to (6) above, wherein the dispatch unit disables the functional unit corresponding to the region where the local heat generation problem is detected. (8) In a circuit for distributing instructions to one of a plurality of functional circuits, each of which is positioned within various regions of an integrated circuit, the first located within the first region of the integrated circuit. A functional circuit and a first circuit for measuring or predicting power consumption in a first region of an integrated circuit and generating a first signal for measurement or predicted power consumption in the first region. A second functional circuit and an integrated circuit that are positioned within the second region of the integrated circuit and allow the first and second functional units to perform approximately the same function in response to instructions. A second circuit for measuring or predicting power consumption in the second region and generating a second signal for measurement or predicted power consumption in the second region, and a first signal and a second signal. When the power consumption in the second region exceeds a given amount, the first functional circuit is processed, and when the power consumption in the first region exceeds a given amount, the second function is processed. A circuit characterized in that the circuit includes a circuit for routing instructions for performing an operation. (9) The first circuit measures or predicts the power consumption in the first region with the first power sensing circuit, and the measurement or predicted power consumption in the first region with the first predetermined amount. By comparison, the second circuit includes a first discrimination circuit that generates a first signal when the power consumption in the first region exceeds the first predetermined amount, and the second circuit is in the second region. The power consumption in the second region is the second, comparing the measured or predicted power consumption in the second region with the second predetermined amount with the second power sensing circuit that measures or predicts the power consumption of the second region. The circuit according to (8) above, comprising a second discrimination circuit that generates a second signal when a predetermined amount is exceeded. (10) A unit power cutoff control circuit in which the processing circuit receives and processes a first signal and a second signal, and selects one of the first or second functional units to receive an instruction. And to further include a dispatch unit to dispatch the instruction to the functional unit selected for execution of the instruction, thereby reducing the effects of local heat generation in the area containing the unselected functional unit. The circuit according to (9) above, which is a feature. (11) The circuit according to (10) above, wherein the dispatch unit disables a functional unit that has not been selected. (12) A unit power cutoff control circuit in which the processing circuit receives and processes a first signal and a second signal, and selects one of the first or second functional units to receive an instruction. And to further include a dispatch unit to dispatch the instruction to the functional unit selected for execution of the instruction, thereby reducing the effects of local heat generation in the area containing the unselected functional unit. The circuit according to (8) above, which is a feature. (13) The circuit according to (12) above, wherein the dispatch unit disables a functional unit that has not been selected. (14) In a method for reducing power-related local heat generation on an integrated circuit, a step of providing a first functional unit on the integrated circuit in the first region of the integrated circuit and a step in the second region of the integrated circuit. Including the step of providing a second functional unit on the integrated circuit, the first functional unit and the second functional unit can perform almost the same function in response to an instruction, and further, the first of the integrated circuit A step to determine if there is a local heat generation problem in the region of the integrated circuit, a step to determine if there is a local heat generation problem in the second region of the integrated circuit, and a position in the region having the local heat generation problem. Not in one of the first or second functional units, or in the first or second functional unit if the local heat problem is present in both the first and second regions. A method characterized in that one of them includes a step of dispatching instructions. (15) The step of dispatching an instruction includes a step of enabling a functional unit to which the instruction is dispatched and a step of disabling a functional unit located in an area having a local heat generation problem. The method according to (14) above, which is characteristic. (16) The step of determining whether or not there is a local heat generation problem in the first region is a step of measuring or predicting power consumption in the first region, and a first predetermined measurement or predicted power consumption. A local heat generation problem exists in the second region, including a step of determining that a local heat generation problem exists in the first region when the power consumption exceeds the first predetermined amount as compared with the amount of. The step of determining whether or not is the step of measuring or predicting the power consumption in the second region and comparing the measured or predicted power consumption with the second predetermined amount, and the power consumption is the second predetermined amount. The method according to (14) above, which comprises a step of determining that a local heat generation problem exists in the second region when the value exceeds. (17) The step of dispatching an instruction includes a step of enabling a functional unit to which the instruction is dispatched and a step of disabling a functional unit located in an area having a local heat generation problem. The method according to (16) above, which is characteristic.

[Simple explanation of drawings]

[Figure 1]

It is an overall block diagram of the system by this invention.

[Figure 2]

It is a detailed figure of the power prediction circuit shown in FIG.

[Fig. 3]

It is a detailed figure of a power cutoff control unit.

[Fig. 4]

It is a basic flow diagram of the method for dispatching an instruction to one of the functional units.

[Explanation of symbols]

100 devices 102 Neighboring area of unit # 1 Neighborhood area of 104 unit # 2 106 Type X Unit # 1 108 Type X Unit # 2 110 Neighborhood power prediction circuit 112 Neighborhood power prediction circuit 114 Dispatch unit 116 Power cutoff control unit 118 signal line 120 signal line 122 signal line 124 signal line 150 functional units 151 Functional unit 152 functional unit 153 Functional unit 154 functional unit 155 functional unit 156 Functional unit 157 functional unit 158 functional unit 159 functional unit 160 functional unit 198 Integrated circuit