Digital Equipment PCI32-VME64, Руководство пользователя

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Introduction to the PCI32-VME64 Adapter
1–6 DIGITAL PCI32-VME64 Adapter Hardware Owner's Guide
1.4.4 VMEbus Bridge Module
The VMEbus bridge module (VBM) is a single 6U VME module that interfaces between the
64-bit VMEbus and the interconnect cable. This module contains the VIC64 VMEbus
interface chip and its companion chips to form the VME 64 interface. The module also
contains registers for memory mapping, hardware-assisted byte swapping, and address and
data buffering to allow for asynchronous communication between the interconnect cable and
the VMEbus. The VIC64 and the associated companion chips (CY7C964’s) are the VME 64
interface.
1.4.5 Interconnect Cable
The interconnect cable is a high-speed, point-to-point interconnect that joins the PCI bus
bridge module and the VMEbus bridge module. The cable contains multiplexed, parity-
protected address and data lines as well as command lines. Two simplex 16-bit data paths
with a positive acknowledge protocol provide a raw bandwidth of 80 MB/s in each direction.
A four-bit command bus also connects the two modules. All data is transferred in 32-bit word
entities using LVDS fully differential drivers and receivers through twisted-pair wires. The
LVDS technology features a low-voltage differential signal and fast transition times. The low
voltage minimizes power use while maximizing data rates.
1.4.6 System Controller Jumper
The system controller jumper, labeled W1, is located on the VMEbus bridge module. When
this jumper is installed, the module handles all the functions of a VMEbus system controller.
When the jumper is not installed, the module handles daisy chains and bus grants, as would
any other module in the system.
Table 1-2 VMEbus Bridge Module System Controller Jumper Setting
W1 Definition
In System Controller
Out Not System Controller
Figure 1-3 System Controller Jumper Location
ML013587