Embodiments generally relate to the design of printed circuit board (PCB) layouts (e.g., “floorplans”). More particularly, embodiments relate to artificial intelligence (AI) based floorplanning for PCB design.
A PCB may include several components of varying shapes, wherein the placement and orientation of the components on the PCB is typically determined manually. Such an approach may be time consuming and often results in suboptimal surface area usage on the PCB.
The various advantages of the embodiments will become apparent to one skilled in the art by reading the following specification and appended claims, and by referencing the following drawings, in which:
As will be discussed in greater detail, AI-based technology described herein automatically determines the aspect ratios of the functional blocks 22, 24 and the layout/floorplan of the functional blocks 22, 24 within the circuit 20. More particularly, assuming there are N functional blocks and the ith block includes Mi rectangle components, the technology described herein determines the best location and shape of each functional block so that all of the functional blocks fit into a board outline of minimal area. Accordingly, the AI-based technology provides for faster floorplanning and reduced surface area usage on the PCB.
Turning now to
Rather than attempting to enumerate all possible options 30, 32 for each functional block, the area to place the components for each functional block can be estimated. Assuming that the ith block includes Mi rectangle components, the size of each component is wij×hij, (j=1, 2, . . . , Mi), and the spacing between two components is at least d, the area of the ith rectangle block can be estimated to be:
A
i=αΣj=1M
Given that the components are of various sizes, a scaling factor α is introduced to control the amount of space that is “wasted” in the block. In one example, the value of α is between 1.1 and 1.3, depending on the market segment and PCB technology. To find an accurate α for a new product, the PCB boards for past products may be analyzed to determine the α for the functional blocks on the past PCB boards, wherein the average α can be an accurate α for the current circuit.
Once the area of each functional block is determined, the size of the functional block can be controlled using an aspect ratio
Therefore, the area Ai=Wi×Hi=riHi2. The minimum value of ri is 1 when the block is a square. The maximum value of ri is determined by the largest component in the functional block. In that case, Hi=max(hij), then
Accordingly, the range of the aspect ratio of the ith block is:
To determine a floorplan, both the shape and the location of each functional block is determined. Based on the aforementioned approach, the block shape is controlled by the aspect ratio ri.
Turning now to
In an embodiment, the shape of each functional block is governed by the aspect ratio ri, and the geometric relationship of all functional blocks is governed by the B*-Tree 50. The optimization problem therefore becomes finding the optimal ri and the optimal B*-Tree 50 that results in the smallest board area. To solve this optimization problem, AI-based technology described herein automatically finds the best floorplan 54 with minimal board area. In one example, the technology involves a two-level optimization:
1) Use Bayesian Optimization to optimize aspect ratio ri of each functional block; and
2) For each aspect ratio proposed in operation 1), simulated annealing optimization is used to find the best floorplan 54 with the minimal board area.
Computer program code to carry out operations shown in the method 60 can be written in any combination of one or more programming languages, including an object oriented programming language such as JAVA, SMALLTALK, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. Additionally, logic instructions might include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, state-setting data, configuration data for integrated circuitry, state information that personalizes electronic circuitry and/or other structural components that are native to hardware (e.g., host processor, central processing unit/CPU, microcontroller, etc.).
Illustrated processing block 62 provides for identifying a plurality of functional blocks in a circuit, wherein each functional block includes a plurality of components. In one example, processing block 62 involves identifying size data associated with the components. Processing block 64 conducts one or more passes (e.g., iterations, repeats) of a first optimization loop to determine candidate aspect ratios of the components in the functional blocks based on the size data associated with the components. In an embodiment, processing block 64 also determines the range of aspect ratios for each functional block. The first optimization loop may include a Bayesian optimization update of a surrogate model of the circuit based on the candidate floorplan data.
More particularly, to find the global minimal board area (e.g., objective function) given N modules with certain aspect ratio ranges and no explicit objective function for the problem, a “black box” approach may be used. Bayesian optimization is a sequential design strategy for global optimization of black box functions that does not assume any functional forms. The Bayesian strategy is to treat the minimal area problem as a random function and place a “prior” over the function, wherein the prior captures beliefs about the behavior of the function. After gathering the function evaluations (e.g., after a few iterations, area data for some aspect ratios is obtained), which are treated as data, the prior is updated to form the posterior distribution over the objective function. The posterior distribution, in turn, is used to construct an acquisition function (e.g., “infill sampling criteria”) that determines the next query point, which is the next aspect ratio to test and gather data.
With regard to the surrogate model, Bayesian optimization approaches this finding global minimal area task through a method known as surrogate optimization. A surrogate function is an approximation of the objective function. The surrogate function is formed based on sampled points. Based on the surrogate function, processing block 64 can identify which points are promising minima. More sampling is conducted from these promising regions and the surrogate function is updated accordingly. Thus, the surrogate model may be the interior model used by Bayesian optimization.
Illustrated processing block 66 conducts, within the one or more passes of the first optimization loop, one or more passes of a second optimization loop to determine candidate floorplan data for the circuit based on the candidate aspect ratios. In one example, the second optimization loop includes a simulated annealing optimization with respect to a B*-Tree representation of the candidate floorplan data. Additionally, the simulated annealing optimization may include a plurality of random perturbation operations such as, for example, rotating a functional block randomly selected from all functional blocks, moving a randomly selected functional block to another randomly selected location, swapping two randomly selected functional blocks, and so forth. Processing block 68 exits the second optimization in response to a second time constraint (e.g., time budget). In an embodiment, processing block 70 exits the first optimization loop in response to a first time constraint. Block 70 may also include automatically outputting the floorplan associated with the smallest surface area. The method 60 therefore enhances performance at least to the extent that automating the nested optimization loops saves time and/or reduces surface area usage on the PCB.
In general, the method 80 involves two optimization loops. The outer loop is used by Bayesian Optimization to optimize the aspect ratio, while the inner loop is used by simulated annealing to optimize the location of each functional block. Simulated annealing relies on random perturbation to generate new B*-Tree. As already noted, the random operations might include:
Rotating a functional block randomly selected from all functional blocks;
Moving a randomly selected functional block to another randomly selected location; and
Swapping two randomly selected functional blocks.
A time budget may be set for both the Bayesian optimization (BO) and the simulated annealing. When the iterative optimization loop exceeds the time budget, the optimization loop is exited. Since simulated annealing is a probabilistic technique to approximate a global optimum of a given function, a time budget of, for example, 30 seconds (s) may be set to finish one optimization loop. Therefore, Bayesian optimization is used in the outer loop to improve data efficiency. Once the Bayesian optimization time budget is met, the method 80 will output the best floorplan.
More particularly, illustrated processing block 82 identifies the size of each component in a circuit as an input. Processing block 84 calculates the range of the aspect ratio of each functional block. A determination may be made at processing block 86 as to whether the termination condition (e.g., time budget, all combinations have been attempted) for the Bayesian optimization has been met. If not, processing block 88 uses the current surrogate model of the floorplan to propose the most promising value of the aspect ratios (e.g., candidate aspect ratios). In an embodiment, processing block 90 builds an initial B*-Tree based on the candidate aspect ratios. Processing block 90 may also enforce relative position conditions such as, for example, ensuring that an instruction set architecture (ISA) functional block is next to a power management block. Illustrated processing block 92 randomly perturbs the B*-Tree (e.g., rotating a functional block randomly selected from all functional blocks, moving a randomly selected functional block to another randomly selected location, swapping two randomly selected functional blocks, etc.).
In one example, processing block 94 applies a boundary condition to the B*-Tree. Additionally, a determination may be made at processing block 96 as to whether the termination condition (e.g., time budget) for simulated annealing has been met. If not, the method 80 returns to processing block 92 and another pass of the simulated annealing optimization loop is conducted. Otherwise, processing block 98 reports the lower-left corner vertex coordinate corresponding to the floorplan with the smallest area. Processing block 100 updates the surrogate model of the floorplan with the lower-left corner vertex coordinate reported by processing block 98. In one example, the method 80 then returns to processing block 86. Once the termination condition for the Bayesian optimization is met, processing block 100 outputs the best floorplan.
Turning now to
In the illustrated example, the system 280 includes a host processor 282 (e.g., CPU) having an integrated memory controller (IMC) 284 that is coupled to a system memory 286 (e.g., dual inline memory module/DIMM). In an embodiment, an IO (input/output) module 288 is coupled to the host processor 282. The illustrated IO module 288 communicates with, for example, a display 290 (e.g., touch screen, liquid crystal display/LCD, light emitting diode/LED display), mass storage 302 (e.g., hard disk drive/HDD, optical disc, solid state drive/SSD) and a network controller 292 (e.g., wired and/or wireless). The host processor 282 may be combined with the IO module 288, a graphics processor 294, and an AI accelerator 296 into a system on chip (SoC) 298.
In an embodiment, the host processor 282 and/or the AI accelerator 296 executes a set of program instructions 300 retrieved from the mass storage 302 and/or the system memory 286 to perform one or more aspects of the method 60 (
The logic 354 may be implemented at least partly in configurable or fixed-functionality hardware. In one example, the logic 354 includes transistor channel regions that are positioned (e.g., embedded) within the substrate(s) 352. Thus, the interface between the logic 354 and the substrate(s) 352 may not be an abrupt junction. The logic 354 may also be considered to include an epitaxial layer that is grown on an initial wafer of the substrate(s) 352.
The processor core 400 is shown including execution logic 450 having a set of execution units 455-1 through 455-N. Some embodiments may include a number of execution units dedicated to specific functions or sets of functions. Other embodiments may include only one execution unit or one execution unit that can perform a particular function. The illustrated execution logic 450 performs the operations specified by code instructions.
After completion of execution of the operations specified by the code instructions, back end logic 460 retires the instructions of the code 413. In one embodiment, the processor core 400 allows out of order execution but requires in order retirement of instructions. Retirement logic 465 may take a variety of forms as known to those of skill in the art (e.g., re-order buffers or the like). In this manner, the processor core 400 is transformed during execution of the code 413, at least in terms of the output generated by the decoder, the hardware registers and tables utilized by the register renaming logic 425, and any registers (not shown) modified by the execution logic 450.
Although not illustrated in
Referring now to
The system 1000 is illustrated as a point-to-point interconnect system, wherein the first processing element 1070 and the second processing element 1080 are coupled via a point-to-point interconnect 1050. It should be understood that any or all of the interconnects illustrated in
As shown in
Each processing element 1070, 1080 may include at least one shared cache 1896a, 1896b. The shared cache 1896a, 1896b may store data (e.g., instructions) that are utilized by one or more components of the processor, such as the cores 1074a, 1074b and 1084a, 1084b, respectively. For example, the shared cache 1896a, 1896b may locally cache data stored in a memory 1032, 1034 for faster access by components of the processor. In one or more embodiments, the shared cache 1896a, 1896b may include one or more mid-level caches, such as level 2 (L2), level 3 (L3), level 4 (L4), or other levels of cache, a last level cache (LLC), and/or combinations thereof.
While shown with only two processing elements 1070, 1080, it is to be understood that the scope of the embodiments are not so limited. In other embodiments, one or more additional processing elements may be present in a given processor. Alternatively, one or more of processing elements 1070, 1080 may be an element other than a processor, such as an accelerator or a field programmable gate array. For example, additional processing element(s) may include additional processors(s) that are the same as a first processor 1070, additional processor(s) that are heterogeneous or asymmetric to processor a first processor 1070, accelerators (such as, e.g., graphics accelerators or digital signal processing (DSP) units), field programmable gate arrays, or any other processing element. There can be a variety of differences between the processing elements 1070, 1080 in terms of a spectrum of metrics of merit including architectural, micro architectural, thermal, power consumption characteristics, and the like. These differences may effectively manifest themselves as asymmetry and heterogeneity amongst the processing elements 1070, 1080. For at least one embodiment, the various processing elements 1070, 1080 may reside in the same die package.
The first processing element 1070 may further include memory controller logic (MC) 1072 and point-to-point (P-P) interfaces 1076 and 1078. Similarly, the second processing element 1080 may include a MC 1082 and P-P interfaces 1086 and 1088. As shown in
The first processing element 1070 and the second processing element 1080 may be coupled to an I/O subsystem 1090 via P-P interconnects 10761086, respectively. As shown in
In turn, I/O subsystem 1090 may be coupled to a first bus 1016 via an interface 1096. In one embodiment, the first bus 1016 may be a Peripheral Component Interconnect (PCI) bus, or a bus such as a PCI Express bus or another third generation I/O interconnect bus, although the scope of the embodiments are not so limited.
As shown in
Note that other embodiments are contemplated. For example, instead of the point-to-point architecture of
Example 1 includes a performance-enhanced computing system comprising a network controller, a processor coupled to the network controller, and a memory coupled to the processor, the memory including a set of instructions, which when executed by the processor, cause the processor to identify a plurality of functional blocks in a circuit, wherein each functional block includes a plurality of components, conduct one or more passes of a first optimization loop to determine candidate aspect ratios for the functional blocks based on size data associated with the components, and conduct, within the one or more passes of the first optimization loop, one or more passes of a second optimization loop to determine candidate floorplan data for the circuit based on the candidate aspect ratios.
Example 2 includes the computing system of Example 1, wherein the second optimization loop is to include a simulated annealing optimization with respect to a B*-Tree representation of the candidate floorplan data.
Example 3 includes the computing system of Example 2, wherein the simulated annealing optimization is to include a plurality of random perturbation operations.
Example 4 includes the computing system of any one of Examples 1 to 3, wherein the instructions, when executed, further cause the processor to exit the second optimization loop in response to a second time constraint.
Example 5 includes the computing system of Example 1, wherein the first optimization loop is to include a Bayesian optimization update of a surrogate model of the circuit based on the candidate floorplan data.
Example 6 includes the computing system of any one of Examples 1 to 5, wherein the instructions, when executed, further cause the processor to exit the first optimization loop in response to a first time constraint, and output a floorplan associated with a smallest surface area.
Example 7 includes at least one computer readable storage medium comprising a set of instructions, which when executed by a computing system, cause the computing system to identify a plurality of functional blocks in a circuit, wherein each functional block includes a plurality of components, conduct one or more passes of a first optimization loop to determine candidate aspect ratios for the functional blocks based on size data associated with the components, and conduct, within the one or more passes of the first optimization loop, one or more passes of a second optimization loop to determine candidate floorplan data for the circuit based on the candidate aspect ratios.
Example 8 includes the at least one computer readable storage medium of Example 7, wherein the second optimization loop is to include a simulated annealing optimization with respect to a B*-Tree representation of the candidate floorplan data.
Example 9 includes the at least one computer readable storage medium of Example 8, wherein the simulated annealing optimization is to include a plurality of random perturbation operations.
Example 10 includes the at least one computer readable storage medium of any one of Examples 7 to 9, wherein the instructions, when executed, further cause the computing system to exit the second optimization loop in response to a second time constraint.
Example 11 includes the at least one computer readable storage medium of Example 7, wherein the first optimization loop is to include a Bayesian optimization update of a surrogate model of the circuit based on the candidate floorplan data.
Example 12 includes the at least one computer readable storage medium of any one of Examples 7 to 11, wherein the instructions, when executed, further cause the computing system to exit the first optimization loop in response to a first time constraint, and output a floorplan associated with a smallest surface area.
Example 13 includes a semiconductor apparatus comprising one or more substrates, and logic coupled to the one or more substrates, wherein the logic is implemented at least partly in one or more of configurable or fixed-functionality hardware, the logic to identify a plurality of functional blocks in a circuit, wherein each functional block includes a plurality of components, conduct one or more passes of a first optimization loop to determine candidate aspect ratios for the functional blocks based on size data associated with the components, and conduct, within the one or more passes of the first optimization loop, one or more passes of a second optimization loop to determine candidate floorplan data for the circuit based on the candidate aspect ratios.
Example 14 includes the semiconductor apparatus of Example 13, wherein the second optimization loop is to include a simulated annealing optimization with respect to a B*-Tree representation of the candidate floorplan data.
Example 15 includes the semiconductor apparatus of Example 14, wherein the simulated annealing optimization is to include a plurality of random perturbation operations.
Example 16 includes the semiconductor apparatus of any one of Examples 13 to 15, wherein the logic is to exit the second optimization loop in response to a second time constraint.
Example 17 includes the semiconductor apparatus of Example 13, wherein the first optimization loop is to include a Bayesian optimization update of a surrogate model of the circuit based on the candidate floorplan data.
Example 18 includes the semiconductor apparatus of any one of Examples 13 to 17, wherein the logic is to exit the first optimization loop in response to a first time constraint, and output a floorplan associated with a smallest surface area.
Example 19 includes the semiconductor apparatus of any one of Examples 13 to 18, wherein the logic coupled to the one or more substrates includes transistor channel regions that are positioned within the one or more substrates.
Example 20 includes a method of operating a performance-enhanced computing system, the method comprising identifying a plurality of functional blocks in a circuit, wherein each functional block includes a plurality of components, conducting one or more passes of a first optimization loop to determine candidate aspect ratios for the functional blocks based on size data associated with the components, and conducting, within the one or more passes of the first optimization loop, one or more passes of a second optimization loop to determine candidate floorplan data for the circuit based on the candidate aspect ratios.
Example 21 includes the method of Example 20, wherein the second optimization loop includes a simulated annealing optimization with respect to a B*-Tree representation of the candidate floorplan data.
Example 22 includes the method of Example 21, wherein the simulated annealing optimization includes a plurality of random perturbation operations.
Example 23 includes the method of any one of Examples 20 to 22, further including exiting the second optimization loop in response to a second time constraint.
Example 24 includes the method of Example 20, wherein the first optimization loop includes a Bayesian optimization update of a surrogate model of the circuit based on the candidate floorplan data.
Example 25 includes the method of any one of Examples 20 to 24, further including exiting the first optimization loop in response to a first time constraint, and outputting a floorplan associated with a smallest surface area.
Example 26 includes an apparatus comprising means for performing the method of any one of Examples 20 to 25.
Embodiments are applicable for use with all types of semiconductor integrated circuit (“IC”) chips. Examples of these IC chips include but are not limited to processors, controllers, chipset components, programmable logic arrays (PLAs), memory chips, network chips, systems on chip (SoCs), SSD/NAND controller ASICs, and the like. In addition, in some of the drawings, signal conductor lines are represented with lines. Some may be different, to indicate more constituent signal paths, have a number label, to indicate a number of constituent signal paths, and/or have arrows at one or more ends, to indicate primary information flow direction. This, however, should not be construed in a limiting manner. Rather, such added detail may be used in connection with one or more exemplary embodiments to facilitate easier understanding of a circuit. Any represented signal lines, whether or not having additional information, may actually comprise one or more signals that may travel in multiple directions and may be implemented with any suitable type of signal scheme, e.g., digital or analog lines implemented with differential pairs, optical fiber lines, and/or single-ended lines.
Example sizes/models/values/ranges may have been given, although embodiments are not limited to the same. As manufacturing techniques (e.g., photolithography) mature over time, it is expected that devices of smaller size could be manufactured. In addition, well known power/ground connections to IC chips and other components may or may not be shown within the figures, for simplicity of illustration and discussion, and so as not to obscure certain aspects of the embodiments. Further, arrangements may be shown in block diagram form in order to avoid obscuring embodiments, and also in view of the fact that specifics with respect to implementation of such block diagram arrangements are highly dependent upon the computing system within which the embodiment is to be implemented, i.e., such specifics should be well within purview of one skilled in the art. Where specific details (e.g., circuits) are set forth in order to describe example embodiments, it should be apparent to one skilled in the art that embodiments can be practiced without, or with variation of, these specific details. The description is thus to be regarded as illustrative instead of limiting.
The term “coupled” may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms “first”, “second”, etc. may be used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.
As used in this application and in the claims, a list of items joined by the term “one or more of” may mean any combination of the listed terms. For example, the phrases “one or more of A, B or C” may mean A; B; C; A and B; A and C; B and C; or A, B and C.
Those skilled in the art will appreciate from the foregoing description that the broad techniques of the embodiments can be implemented in a variety of forms. Therefore, while the embodiments have been described in connection with particular examples thereof, the true scope of the embodiments should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.