Embedded Pc/Rtos Features; Vme Bridge - GE VMIVME-7805 Hardware Reference Manual

3 • Embedded PC/RTOS Features

3.1 VME Bridge

GE VMIVME-7805/VME-7805RC feature additional capabilities beyond those of a
typical desktop computer system. The unit provides four software-controlled,
general-purpose timers along with a programmable Watchdog Timer for
synchronizing and controlling multiple events in embedded applications. The
VMIVME-7805/VME-7805RC also provide a CompactFlash system and 32 KByte
of nonvolatile SRAM. Also, the
VMIVME-7805/VME-7805RC support an embedded intelligent VME bridge to
allow compatibility with the most demanding VME applications. These features
make the unit ideal for embedded applications, particularly where standard hard
drives and floppy disk drives cannot be used. The VMIVME-7805/VME-7805RC
2
also support I C by integrating specialized circuitry for these functions.
In addition to their PC/AT functions, the VMIVME-7805/VME-7805RC have the
following VME features:
• Complete six-line Address Modifier (AM-Code) programmability
• VME data interface with separate hardware byte/word swapping for master
and slave accesses
• Support for VME64 multiplexed MBLT 64-bit VME block transfers
• User-configured interrupter
• User-configured interrupt handler
• System Controller mode with programmable VME arbiter (PRI, SGL and
RRS modes are supported)
• VME BERR bus error timer (software programmable)
• Slave access from the VME to local RAM and mailbox registers
• Full-featured programmable VME requester (ROR, RWD and BCAP modes
are supported)
• System Controller auto detection
• Complete VME master access through five separate Protected-mode mem-
ory windows
The VMIVME-7805/VME-7805RC support High Throughput DMA transfers of
bytes, words and longwords in both Master and Slave configurations.
If Endian conversion is not needed, GE offers a special "Bypass" mode that can be
used to further enhance throughput (not available for byte transfers).
The VMIVME-7805/VME-7805RC VME interface is provided by the PCI-to-VME
bridge built around the Tundra Semiconductor Corporation Universe II VME
interface chip. The Universe II provides a reliable high-performance 64-bit VME-
to-PCI interface in one design. The functions and programming of the Universe-
based VME interface are addressed in detail in a companion manual titled:
GE Intelligent Platforms' Tundra Universe II Based VME Interface Product Manual
(500-000211-000).

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