• deconfiguring FPGAs on all mini-PCI modules and the baseboard memory controller FPGAs.
• setting the PCI and DSP module (DM2C31 and DM4C51) clock generators to low frequencies.

Setting and recovering from low-power mode is performed using the pciinit program. The new -L option causes all the V6M6 boards specified to be put into low-power mode. For example:

    pciinit -L pci0
    pciinit -L all

To bring the boards back to normal operating mode use pciinit with the -R (hard reset) option.

V6M6 requirements for this capability are:

• A version 2 V6M6 board with VME interface FPGA configuration flash object version, vmepcib108.mcs.
• Version 1.22 of the Software Support Library (included with V6M6 Software Release 1.4.5).

Current host system requirements:

• Operating system: Solaris 2.5 or above.
• Processor board: Force Computers CPU-5V, CPU-5VT, CPU-7V, CPU-8VT, CPU-20VT and CPU-24VT (with Force Computer's VME device driver version 2.0.4 or above).

Support for this capability will eventually be provided for processor boards. Please note that because the access to the DMA controller is hardware and operating system dependent, binary files compiled on one system type may not be copied to a system of another type.

Data transfers are performed on arrays of 32-bit words. The array should be allocated aligned on a page boundary (4096). The actual required alignment may vary from system but a value of 4096 should be safe for any system. Memory can be allocated on a specific alignment using the memalign. system function. For example:

    u_long *data = (u_long *) memalign(4096, num_bytes) ;

The transfers are done by accessing a special address range within the V6M6's address VME address space. The bridge to the PCI address space is handled by the V6M6's H host resource. Programs using host-driven DMA must obtain access to the H resource and prepare its registers. This initialization is performed by the pci_hostdma_setup function, described below. The V6M6 hardware can handle individual transfers of up to 8K words (32,768 bytes), within its special VME address range. The library functions break up larger arrays into blocks of 8,192 words passing each block to the CPU's DMA controller.