Performance Analysis of Processor Midterm Presentation Performed by : Winter 2005 Alexei Iolin Alexander Faingersh Instructor: Evgeny Fiksman

Agenda Project Goals MicroBlaze architecture OPB timer/counter OPB interrupt controller Connecting Customized IP to FSL bus Our Customized IP Performance result

Project Goals Examination of MicroBlaze calculation abilities by measuring time of running application and power consumption. Implementing arbitrary application in Hardware (IDCT) and using it as a hardware acceleration for MicroBlaze. Implementing the same functionality in C and comparing the results with hardware. Adding self written C code for testing FPU. Using as application code one of well known benchmarks. Such as: DHRYSTONE MIPS,SPEC CPU Or implementing arbitrary benchmark. MicroBlaze is a Soft core Processor developed by Xilinx that meets performance, area-efficiency and low cost targets. Although using the MicroBlaze enables fast system development on a single FPGA, some of the “special” applications run slower than in Hardware IP. We will examine this with EDK environment

Hardware

EDK and MicroBlaze The Embedded Development Kit (EDK) is a set of microprocessor design tool and common software platforms. The EDK includes the Platform Studio tool suite, the MicroBlaze core and a library of peripheral IP cores. The MicroBlaze embedded soft core is a 32-bit Reduced Instruction Set Computer (RISC) optimized for implementation in FPGA. Operating at up to 200 MHz. MicroBlaze enables to you have complete flexibility in setting peripherals, memory and interface features on a single FPGA

MicroBlaze Architecture MicroBlaze Hardware Options and Functions Hardware Barrel Shifter Hardware Divider Machine Status Set and Clear Instructions Hardware Exception Support Pattern Compare Instructions Floating-Point Unit (FPU) Hardware Multiplier Enable Bus Infrastructure Data-side On-chip Peripheral Bus (DOPB) Instruction-side On-chip Peripheral Bus (IOPB) Data-side Local Memory Bus (DLMB) Instruction-side Local Memory Bus (ILMB) Fast Simplex Link (FSL)

OPB Timer/Counter The TC (Timer/Counter) is a 32-bit timer module that attaches to the OPB. Two programmable interval timers with interrupt, event generation, and eventcapture capabilities. Each timer has 3 32bit registers: 1. TCSR - Control Register 2. TLR - Load Register 3. TCR - Counter Register Both timer/counter modules can be used in a Generate Mode, a Capture Mode, or a Pulse Width Modulation (PWM) Mode.

OPB Interrupt Controller

Continuing INTC… INTC Features Priority between interrupt requests is determined by vector position. Supports data bus widths of 8-bits, 16-bits, or 32-bits for OPB interface. Number of interrupt inputs configurable up to the width of data bus. Interrupt Enable Register (IER) for selectively disabling individual interrupt inputs. Master Enable Register for disabling interrupt request output and choosing software or hardware interrupts. Each input is configurable for edge or level sensitivity.

Connecting Customized IP to FSL BUS MicroBlaze has the ability to use its dedicated FSL bus interface to integrate a customized IP core into a MicroBlaze soft processor-based system. Generally, there are two ways to integrate a customized IP core into a MicroBlaze 1.One way is to connect the IP on the (OPB). 2. The second way is to connect the user IP to the MicroBlaze dedicated Fast Simplex Link (FSL) bus system. If the application is time-critical, the designer should take bus standard delays into account, thus the user IP should be connected to the FSL bus system. Otherwise, it can be connected as a slave or master on the OPB.

Continuing Customized IP… In general, every application can be realized and implemented either as software algorithm or as structural hardware. It is important to use the hardware implementation advantage (parallel execution). Example demonstrates how the parallel execution advantage can be used. The software routine needs 12 clock cycles to calculate the result G. However, in hardware it takes only 2 clock cycles to compute the same result.

RISC architectures have a two-input and a one-output (ALU). IP with more than two input values and more than one output value are problematical. If the critical path of the whole system is through the user IP, the whole soft processor will decrease in performance (processor frequency). The software integration of customized instruction can’t be handled directly from the compiler, thus the user has to use inline assembly to work with them. The customized instructions have to be implemented in software as inline assembler code. This could produce a C application code, which is neither very clean nor portable. It is possible to use more than 2 dynamic inputs and more than 1 output because up to 16 FSL interface busses are provided. User IP is independent, doesn’t affect the internal MB RISC architecture thus won’t decrease the clock frequency of MB. Outside implementation of IP allows to run customs calculations parallel to main stream application. The new hardware doesn't require inline assembler code because the FSL interface has predefined C- macros for I/O to IP Two MB processors connected back to back have a very fast and clean way to communicate with each other.

We implemented 1-dimension IDCT on FSL. A 1-dimension IDCT realized in software requires a high execution time because the C- program executes many loops sequentially. Implementation of application as hardware module greatly reduces the execution time due to parallel processing. The software application writes 8 values from memory to the FSL. The IDCT core gets the data, calculates the result and returns the result data (8 words) back to MB trough the FSL. By cascading the 1-dimensional IDCT core, it is possible to integrate a 2-dimensional IDCT core (Useful for Image processing). Our Customized IP

Continuing Our Customized IP… The whole embedded system consists of the MicroBlaze itself, two FSL bus systems, the user core, an OPB on-chip bus, two OPB peripherals (UART lite and the MicroBlaze Debug module) and the on- chip block RAM. The application program is stored in the on-chip block RAM.

Continuing Our Customized IP FSL_M_Data - The data bus written to the FSL FIFO FSL_M_Write - Input signal that controls the write enable signal of the FIFO. FSL_M_Full - Output signal from the FIFO indicating that the FIFO is full. FSL_S_Data - Output bus that indicates the data available at the read end of the FIFO. FSL_S_Read - Input signal that controls the read acknowledge signal of the FIFO. FSL_S_Exists - Output signal indicating that FIFO contains valid data.

Performance Results Test SpecificationsSW ApplicationTime Testing basic start-up functionality including printing out. Default EDK SW TestApp.c sec Testing the time that takes one entering, printing out and exiting empty interrupt handler. Default EDK SW TestApp.c msec Testing the time that takes to enter the interrupt handler after the interrupt occurred TestApp + Custom IDCT application usec Testing the time for custom IDCT (VHDL)hardware accelerator application TestApp + Custom IDCT application sec

Time Table EDK trainings Studying the communication with OPB Timer and Controller Measuring execution time for basic application files and interrupts. Implementation of IDCT in HW for hardware acceleration Midterm Presentation Implementation of IDCT in C (fixed & FPU version) and power consumption measurements Dhrystone benchmark or arbitrary benchmark Final presentation, poster and Project book DONE 1 WEEK DONE 2 WEEK 3 WEEK

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