Programming on the VMEBus with Xembedded Series
By John H. Sayer
The VMEbus processor can be an intimidating device to program. Just getting started can be a daunting task, where to start? how do you know you can “talk” to the other modules on the VMEbus? Can you talk to the other modules on the VMEbus?
In this series I have brought in sections of our user manual for the XVME-984, Microsoft Windows software support library. With this software you can get on the VMEbus and “talk” to other boards in the backplane in a matter of a few minutes. Most is point, click and enter address and data. In this document we will talk about the use of the VMEbus Manager application. The other applications listed in the overview below will be covered in the coming weeks in this series.
It is important to understand the three major components of the VMEbus; System Controller, Master Interface and Slave Interface. All of the Xembedded VMEbus processors incorporate all three components.
System Controller: Only one module on the VMEbus can be the system controller.
The system controller provides for bus arbitration, a 16 MHz system clock, and the IACK daisy chain driver. This functions major purpose is to determine which bus master get to “talk” on the VMEbus. The Bus Grant function is used to determine who the system controller on the VMEbus is where multiple bus masters are present. Only one module on the VMEbus can be the system controller.
Master Interface: The VMEbus master interface is sometimes referred to as the “TALKER”. Only a module capable of talking on the VMEbus and has been given permission by the system controller to talk on the VMEbus. The master interface is the method to talk between modules on the VMEbus.
Slave Interface: The VMEbus slave interface is sometimes referred to as the “Listener”. Only a module capable of listening on the VMEbus and has been given permission by the system controller to listen on the VMEbus. The slave interface is the method to talk between modules on the VMEbus.
Overview
The XVME-984 Windows® Board Support Package (BSP) is a comprehensive package that simplifies the process of designing VMEbus application programs for Xembedded VME hardware in the Microsoft® Windows 2000 and XP, Vista and Windows® 7 environment.
The Windows® BSP has the following components (distributed on CD):
Installation program
Application Programming Interface (API) used to develop VMEbus applications
Operating system (OS) specific VMEbus device driver
32-bit Dynamic Link Libraries (DLLs)
VMEbus Manager (VMEman) application
XVME Status (XVMEstat) application
VMEbus probe (VMEprobe) application
Dual-access probe (DAprobe) application
Figure 1-1. Component diagram
Boards Supported
The following Xembedded VMEbus processor boards are supported:
| Processor Boards | Details |
| XVME-653 | Single-Slot 233 MHz Intel® Pentium® MMX™ processor; hardware byte-swapping; 0, 32, 64, 128, or 256 MB DRAM; SVGA graphics controller; two serial, one parallel, one USB connectors; floppy/IDE hard disk controllers; 10Base-T/100Base-TX Ethernet. |
| XVME-660 | Two-Slot; 600 MHz Intel Pentium III or 566 MHz Intel Celeron™ processor; hardware byte-swapping; 0, 32, 64, 128, or 256 MB SDRAM; AGP graphics controller; two serial, one parallel, one USB connectors; floppy/IDE hard disk controllers; 10Base-T/100Base-TX Ethernet; PMC site; IP site, UltraSCSI. |
| XVME-661 | Two-Slot; 700 MHz Intel Pentium III processor; hardware byte-swapping; 0, 32, 64, 128, or 256 MB SDRAM; AGP graphics controller; two serial, one parallel, one USB connectors; floppy/IDE hard disk controllers; Dual-10Base-T/100Base-TX Ethernet; PMC site;. |
| XVME-690 | Single-Slot VMEbus Processor with Pentium M 1.8GHz or Celeron M, 256MB to 2GB DRAM, dual Giga-Bit Ethernet, PMC site (PCI-X), USB ports, Serial ports and EIDE and SATA drive interfaces. |
| XVME-689-VR7 | Same P2 VMEBus pinout as a SBS VR7 with Single-Slot VMEbus Processor with Pentium M 1.8GHz or Celeron M, 256MB to 2GB DRAM, dual Giga-Bit Ethernet, PMC site (PCI-X), USB ports, Serial ports and EIDE and SATA drive interfaces. |
| XVME-6200 | Single-Slot VMEbus Processor with Intel Core Duo Processor or Core2 Duo Processor 1.5GHz to 2.16GHz, 512MB to 8GB DRAM, dual Giga-Bit Ethernet, PMC and XMC site, dual Gigabyte Ethernet, USB ports, serial ports and EIDE and SATA drive interfaces. |
VMEbus Manager Application
Xembedded’s VMEbus Manager (VMEMan.exe) is a Win32® application program that gives you a simple mechanism for accessing and monitoring the VMEbus on Xembedded VMEbus PC/AT processors. Xembedded has developed standalone applications to support the VMEbus Manager so that you can test your VMEbus system configuration easily and efficiently. Those applications are:
| Application Name | Description |
| XVMEstat | Displays and monitors the status of VMEbus interrupts, VMEbus control registers, and VMEbus status registers in graphical form. |
| VMEprobe | Reads from and writes to VMEbus dual-access memory; |
| DAprobe | Reads from and writes to PC/AT dual-access memory. |
Accessing the VMEbus
Windows require a device driver to manage the Tundra Universe II, PCI to VMEbus bridge interface. Its responsibilities include:
Managing VMEbus master resources
Managing VMEbus slave resources
Generating VMEbus interrupts
Handling VMEbus and auxiliary interrupts
- Software reset of BIOS
Dynamic Link Libraries (DLLs) provide a 32-bit, high-level application programming interface (API) to the driver. This interface is a comprehensive set of functions that simplifies the development of VMEbus application programs. All of the VMEbus manager tools were written using these libraries.
This chapter describes the API in detail as well as the VMEbus master interface, VMEbus slave interface, and interrupt capability.
VMEbus Master Interface
Xembedded’s VMEbus PC/AT processor modules, which contain a VMEbus master interface, have one or more resources that can be configured to provide a “window” to the VMEbus. The number of resources or “windows” is dependent on the XVME CPU module being used. At a minimum, each “window” is configured with the VMEbus Address Space (A16, A24, A32), VMEbus base address, Program/Data address modifier, and Supervisory/Nonprivileged address modifier. Depending on which XVME CPU module is being used, other configurations such as VMEbus bound address, maximum data width, and cycle type may be configured as well. The device driver accepts VMEbus access requests through the provided API from application programs and configures a “window” accordingly to fulfill the request. The driver also ensures the integrity of the configuration when receiving multiple requests from different processes and/or threads.
VMEbus Slave Interface
Xembedded VMEbus PC/AT processor modules that contain a VMEbus slave interface have one or more resources that can be configured to provide an external “window” to the XVME CPU local memory. The number of resources or “windows” is dependent on the XVME CPU module being used and is configured in the BIOS setup menus (see your XVME CPU hardware manual for information on configuring the VMEbus slave interface). The device driver allocates and reserves the specified amount of local memory from Windows 2000 and XP and maps it accordingly to the “windows.” This memory must be allocated as physically continuous and non-pagable, which can only be done during initialization of the device driver. The device driver accepts access requests to this local memory from application programs through the provided API.
Interrupts
All Xembedded VMEbus PC/AT processor modules are capable of handling interrupts on all seven VMEbus interrupt levels. Some VMEbus PC/AT modules also contain a VMEbus interrupter circuit. This local interrupter allows the VMEbus PC/AT processor module to generate a VMEbus interrupt on any of the seven VMEbus interrupt levels.
Device Driver
The device driver (VMEbus4.sys) is required to access the XVME CPU VMEbus control and status registers and the VMEbus. The functionality built into this driver includes:
VMEbus access
Dual-access memory allocation and access
VMEbus interrupt generation
VMEbus interrupt handling
General access to control registers
- Tundra Universe chip (PCI to VMEbus Bridge) control
XVME4.DLL/XVME.LIB/XVME.H
XVME4.dll provides a 32-bit, high-level interface to the device driver. Programming for the DLL requires users to include the XVME.h header file in their C source code. This header file contains all of the function prototypes and VMEbus constant definitions. After the application has been developed and compiled, it must be linked with the XVME.lib file. This links the application to the DLL so that the functions can be accessed at runtime.
Note
See the appropriate Windows programming manuals for more information on building and linking to DLLs.
XVME.DLL/XVMEISR.DLL
These DLLs are provided to support applications which were developed using the XVME-984/3 Windows 32-bit VMEbus Toolkit. Applications developed with XVME-984/3 will run unmodified with the Windows NT BSP. However, to gain improvements in both performance and functionality, it is necessary to reprogram these applications to use the API documented in this manual.
Library Routines
This table summarizes the library routines, in our next installment we will go into the functions and how they are used.
| Routine | Description |
| auxintAlloc | Allocates an auxiliary interrupt object |
| auxintDisable | Disables an auxiliary interrupt |
| auxintEnable | Enables an auxiliary interrupt |
| auxintFree | Frees up the auxiliary interrupt object allocated by the auxintAlloc |
| auxintWait | Waits for an auxiliary interrupt |
| daAlloc | Returns a pointer to an allocated dual-access memory region |
| daFree | Frees up the dual-access memory region allocated by daAlloc |
| daMove | Copies data from dual-access memory to dual-access memory |
| daRead | Dual-access memory read |
| daRMW | Performs read-modify-write operation on dual-access memory |
| daWrite | Dual-access memory write |
| ioRead8 | Reads an 8-bit value from an I/O port |
| ioRead16 | Reads a 16-bit value from an I/O port |
| ioRead32 | Reads a 32-bit value from an I/O port |
| ioWrite8 | Writes an 8-bit value to an I/O port |
| ioWrite16 | Writes a 16-bit value to an I/O port |
| ioWrite32 | Writes a 32-bit value to an I/O port |
| univRead8 | Reads an 8-bit value from the configuration space of the Universe chip |
| univRead16 | Reads a 16-bit value from the configuration space of the Universe chip |
| univRead32 | Reads a 32-bit value from the configuration space of the Universe chip |
| univWrite8 | Writes an 8-bit value to the configuration space of the Universe chip |
| univWrite16 | Writes a 16-bit value to the configuration space of the Universe chip |
| univWrite32 | Writes a 32-bit value to the configuration space of the Universe chip |
| vmeAlloc | Allocates a VMEbus memory region and returns a pointer |
| vmeFree | Frees up the VMEbus memory region allocated by vmeAlloc |
| vmeMove | Copies data from VMEbus memory to VMEbus memory. |
| vmeRead | VMEbus memory read |
| vmeRMW | Performs read-modify-write operation on VMEbus memory |
| vmeSysReset | Executes a VMEbus SYSRST and restores the state of the Universe chip |
| vmeWrite | VMEbus memory write |
| vmeintAlloc | Allocates a VME interrupt object |
| vmeintDisable | Disables a VME interrupt |
| vmeintEnable | Enables a VME interrupt |
| vmeintFree | Frees up the VME interrupt object allocated by vmeintAlloc |
| vmeintGenerate | Generates a VMEbus interrupt |
| vmeintWait | Waits for a VME interrupt |
| vmeintWaitEx | Waits for a VME interrupt |
VMEbus Manager
The Xembedded VMEbus Manager (VMEMan.exe) is a 32-bit Windows application program that provides a simple mechanism for accessing and monitoring the VMEbus. When using a Xembedded PC/AT processor, the program allows you to quickly test your VMEbus system configuration, by providing a convenient mechanism for reading and writing to VMEbus memory, and monitoring the status of VMEbus interrupts and the PC/AT status registers. This program, like all Windows programs, is menu driven.
Figure 3-1. XVME-984/5 Windows 2000 and XP applications
To execute the VMEman application, select the VMEman icon from the XVME 984-5 group. The VMEman window will open.
Figure 3-2. VMEman window
Clicking the icon in the window title bar or right-clicking anywhere in the title bar will open the System menu, which will allow you to size or close the window.
Figure 3-3. System menu
Monitor Menu
This section describes the menu options associated with the Monitor menu.
Figure 3-4. VMEman Monitor menu
Monitor->XVMEstat
This menu option executes the XVMEstat application, which displays general information about the status of the VMEbus master interface, VMEbus slave interface, and VMEbus interrupts. See Chapter 4 for information on the XVMEstat application.
Monitor->VME IDs
This menu option searches the VMEbus short I/O address space for Xembedded ID PROMs. If any are found, a window is opened and a description of the board is displayed. This description includes the short I/O address where the board resides. If the board found is intelligent, the result of its power-on self test is displayed (PASS/FAIL). If the board is not intelligent, its green LED is turned on and its red LED is turned off.
Figure 3-5. Monitor->VME IDs
Probe Menu
This section describes the menu options associated with the Probe menu.
Figure 3-6. VMEman Probe menu
Probe->VMEprobe
This menu option executes the VMEprobe application, which has the ability to read, write, search, and fill VMEbus memory. See Chapter 5 for information on the VMEprobe application.
Probe->DAprobe
This menu option executes the DAprobe application, which has the ability to read, write, search, and fill dual-access memory. See Chapter 6 for information on the DAprobe application.
Probe->Pass/Fail LEDs
This menu option opens a dialog that allows changing the status of the front panel red and green LEDs on the Xembedded PC/AT VME processor.
Figure 3-7. Pass/Fail LED dialog
Probe->Lock/Unlock VMEbus
This menu option opens a dialog that allows the VMEbus to be obtained using the bus lock bit. The VMEbus will be locked until specifically released by this menu option or by another application.
Figure 3-8. Lock/Unlock VMEbus dialog
Probe->Initiate SYSRST*
This menu option initiates full local and VMEbus resets.
Interrupts Menu
This section describes the menu options associated with the Interrupts menu.
Figure 3-9. VMEman Interrupts menu
Interrupts->Wait for Interrupt
This menu option allows you to specify on which VMEbus levels (1-7) and/or ANMIs (ACFAIL, SYSFAIL, ABORT) to be notified. Once selected, VMEman generates a task displaying the following information:
- A status message indicating that it is waiting for the interrupt
- A message showing the number of interrupts received since it started
- A message showing the number of interrupts per second since it started.
- A “Close” button to quit processing, closing the dialog.
Figure 3-10. Wait for Interrupt dialog
Interrupts->Generate VME Interrupt
This menu option allows you to generate a VMEbus interrupt. If the interrupt cannot be generated, a message box will appear.
Figure 3-11. Generate VME Interrupt dialog
Interrupts->Interrupt Sources
This menu options opens a dialog that allows VMEbus levels 1-7 as well as ACFAIL, SYSFAIL, and ABORT push button interrupts to be enabled or disabled.
Figure 3-12. Interrupt Sources dialog
Configure Menu
This section describes the menu option associated with the Configure menu.
Figure 3-13. VMEman Configure menu
Configure->Master Interface
This menu option opens a dialog that allows driver parameters relating to the master interface to be configured. These parameters are specific to the XVME CPU module being used.
Figure 3-14. Configure Master Interface dialog
Configure->Slave Interface
This menu option opens a dialog that allows driver parameters relating to the slave interface to be configured. These parameters are specific to the XVME CPU module being used.
Figure 3-15. Configure Slave Interface dialog
Configure->Block Hardware
This menu option opens a dialog that allows driver parameters relating to special block transfer hardware to be configured. These parameters are specific to the XVME CPU module being used.
Figure 3-16. Configure Block Hardware dialog
Configure->Interrupt Support
This menu option opens a dialog that allows driver parameters relating to the interrupt support to be configured. These parameters are specific to the XVME CPU module being used.
Figure 3-17. Configure Interrupt Support dialog
Configure->PCI Memory Exclusions
This menu option opens a dialog that allows specified blocks of PCI memory address spaces to be reserved from being used by the driver. This may be necessary when third party drivers are installed which require certain areas of PCI memory space, and that space cannot be dynamically determined by the Xembedded driver.
Figure 3-18. PCI Memory Exclusions dialog
Help Menu
This menu lets you access the BSP help file and the About VMEman window, which displays version information for the VMEman executable, driver, and DLL.
Figure 3-19. VMEman Help menu
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Kevin 12:50 pm on July 1, 2009 Permalink
Excellent Tutorial!!!