User`s manual
Agilent E1490C Description
The Agilent E1490C Breadboard Module is a C-size register-based device
that provides a convenient interface to a VXI mainframe backplane. It
allows you to construct your own custom hardware for use with the
mainframe.
Breadboard Module
Features
The module provides VXI A16/D16 register-based backplane interface
circuitry and metal shields to enclose the printed circuit board. Your VXI
mainframe can communicate with this module configured as an A16/D16
device. The breadboard module interface circuitry is implemented and
accessible according to the requirements outlined in the VXIbus System
Specification.
Users can still provide custom extensions to expand module addressing
capability to A24 or A32 by adding appropriate circuitry according to the
VMEbus and VXIbus System Specification.
Backplane Interface
Features
An overview of the Agilent E1490C interface features follows. See Figure
1-1.
Note For hardware operation, a mnemonic suffixed with an asterisk (such as
WRITE*) indicates inverse logic (0 or low = true; 1 or high = false).
A high state (1) is defined as a positive voltage (usually +5 V) and a low
state (0) is defined as zero V (ground) at the specified signal point.
The Agilent E1490C interface features are:
• Address Lines and Register Decoding. The module implements
15 address lines (A1 - A15) allowing:
1. decoding one of 255 switch-selectable logical device addresses in the
upper fourth of the A16 VME address space, and
2. selecting one of the breadboard configuration registers for read/write
operations. The module decodes the address modifier lines
AM0 - AM5 and acts on codes 29
16
and 2D
16
only.
See page 32 for information about address lines and register decoding.
• Data Lines. Data lines D0 - D15 are available for use on the
breadboard module. These 16 lines are buffered by data bus drivers
and used for writing to, and reading from, the configuration registers
(Status, ID, Device Type, and Control) via an internal data bus
(DB0 - DB15). See page 35 for information about data bus drivers
and data lines.
8 Introduction Chapter 1