University of Toronto ECE532 Digital Hardware Module m05 Adding a User Designed Peripheral Version for EDK 8 2 02i as of January 7 2007 New in EDK 7 1i The Create and Import Peripheral Wizard was introduced in EDK 7 1i to simplify adding user designed peripherals into an EDK repository or an XPS project If you wish to add a peripheral that will be connected to the OPB or PLB bus then this tool should make it much easier See the Embedded System Tools Reference Manual for more information on this wizard This module was created before the Create and Import Peripheral Wizard was available It remains a valuable exercise because it develops an understanding of the underlying structure of an XPS project and provides insight into how to handle a peripheral that might not exactly fit the model of a typical peripheral In this case the core to be added also has a connection directly to the processor not just to the bus Finally it provides an example of how to design a peripheral that connects directly to the OPB bus without Xilinx s IPIF layer and IPIC interface as an intermediary Goals Add a user designed peripheral to a basic MicroBlaze system You will be provided with a core called snoopy that is written in VHDL Demonstrate the required structure necessary for interfacing user designed cores to the Xilinx cores in an XPS project Learn about how you would make your own core to attach to the OPB Requirements Module m01 Building a MicroBlaze System in XPS It is suggested that modules m02 m03 and m04 also be completed before proceeding Preparation Review the handout outlining the EDK project structure provided in Module m01 We will be focusing on the pcores subdirectory for this module If you are unfamiliar with the profiling of code read the manual page for gprof which is accessible on most UNIX systems via the man command and directly from the FSF Background To this point you have only been adding cores from the existing library If you cannot find a core with the required functionality you will have to add your own This lab adds a simple core that can be used to profile the code running on a MicroBlaze This has similar functionality to the gprof utility for profiling that is included in the GNU toolchain However it is much more accurate You may find it useful for your project Step by step 1 Copy your working lab1 project into a new directory called lab5 1 University of Toronto ECE532 Digital Hardware Module m05 Adding a User Designed Peripheral 2 Delete lab5 code lab1 c you don t need it any more 3 Unzip m05 zip into the directory containing lab5 This will add a new program lab5 code system c the custom peripheral lab5 pcores snoopy v1 00 a and some supplemental files 4 Take time to look through the directory structure of the snoopy core The naming structure is essential for XPS to be able to detect a user s peripheral All user cores must be located in the pcores subdirectory or in a globally specified path to a peripheral repository User cores can be defined using Verilog VHDL or a mixture of the two Along with the HDL files used to implement the core the user must also include data files a pao file Peripheral Analyze Order and an mpd file Microprocessor Peripheral Description The former lists the order in which files in your design should be synthesized to resolve component architectures The latter describes the external interface of the core to a system For more information on these files and their structure refer to the Embedded System Tools Guide Notice that the version numbers in the core name and the version numbers in the data file names differ e g version 1 00 a of the snoopy core includes a data file called snoopy v2 1 0 mpd The version in the core name reflects the core s version The version in the data file names reflects the version of the syntax used to write the data file The easiest method for including user IP in an EDK project is to follow an example When you develop your own cores for your project you can use snoopy as a guide The cores provided by Xilinx in the XILINX EDK hw XilinxProcessorIPLib pcores directory may also be used as a reference You are also encouraged to look around through the directories in the EDK installation because there is a lot of source code available that might help you or guide you with your own designs Just as you learn to write good prose by reading good prose you learn to code well by reading good code HDL for IP core can be found in the XILINX EDK hw XilinxProcessorIPLib pcores directory and C code for the drivers can be found in XILINX EDK sw XilinxProcessorIPLib drivers Documentation for the IP cores and drivers can also be found in these directories 5 The snoopy core is a snooping profiler that is able to profile software running on a soft processor in real time The counters calculate the exact number of clock cycles spent executing contiguous address ranges The user specifies the number of counters and the lower and upper bounds for each counter before synthesis This information can be used by embedded system designers to determine which if any sections of the software should be moved to hardware to achieve the required design specifications 6 Lauch XPS and open your lab5 system xmp project Open the IP Catalog tab located in Project Information Area The snoopy core should appear filed under Project Repository Add an instance of the snoopy core by right clicking the core and selecting Add IP The core will appear in the list of System Assembly View Connect it to the slave OPB by clicking the green empty circle associated with the core Switch to the Addresses view and place the new snoopy instance somewhere in the memory map The core requires 256 bytes of address space to be allocated to it aligned at a 256 byte boundary don t forget that the OPB only covers the address space not covered by the ILMB and DLMB i e 0x00010000 0xFFFFFFFF Feel free to check the parameter settings for the core by double clicking on it The default values are fine for now 7 The snoopy core functions by monitoring some trace signals provided by the MicroBlaze These are documented on the MicroBlaze core s datasheet accessible by right clicking on the microblaze 0 entry in the System Assembly View and selecting View PDF Datasheet Specifically the PC EX signal of the snoopy core must be connected to the Trace PC signal provided by the MicroBlaze and the valid instr signal of the snoopy core must be connected to the Trace Valid Instr signal of the MicroBlaze Wire up