Matrix EB002, Руководство пользователя, Страница: 5 / 44

5
Electrical considerations system
E-blocks are built on a bus-based concept
based on D-type connectors. D-types are
used because they are rugged and because
their physical properties allow you to snap
E-blocks together to form a system which
mounts onto a backplane.
Each E-block D-type connector consists
of 8 bits and ground - 9 connections in
total. Upstream boards connect using 9
way D-type sockets (female). Downstream
devices connect to
E-blocks using 9 way
D-type plugs (male).
This combination
works remarkably
well as most system
topologies require
upstream devices to
connect directly to
downstream ones.
On each D-type connector bit 0 is on pin
1, bit 1 is on pin 2, etc. Pin 9 is designated
0V. Where two upstream devices need to
be connected together a gender changer
or Insulation Displacement Connector (IDC)
cable with two IDC sockets on can be used.
Adding power
Power is routed separately between E-blocks
using simple screw terminals and stripped
wires. This facilitates the interpretation
of E-blocks with different voltage levels
(notably 3.3V and 5V). Most downstream
E-blocks are compatible with 3.3V. All
upstream E-blocks have power outputs
on screw terminal connectors. Upstream
E-blocks are powered by applying a higher
voltage via a power jack connector and use
a regulator to generate power for other
E-blocks in the system. As 0V is connected
to all blocks through the 9 way D-type
connectors, it is only necessary to connect
+V to all E-blocks - ground connects via
the D-type. To neaten up more permanent
systems power wires can be looped under
E-blocks and under the backplanes.
Using ZIF sockets
It is possible to use Zero Insertion
Force (ZIF) sockets with those
upstream boards with DIL
sockets. ZIF sockets are
useful where the chips will
be removed from the
programmer many
times. Some E-blocks
boards may have
other components
close to the DIL
socket in question.
If this is the case
then you can simply insert
additional DIL sockets to gain
enough height so that the ZIF socket can be
satisfactorily inserted.
Circuit diagrams
Each E-blocks board has an accompanying
technical datasheet. In the datasheet you
will find a complete description of the
hardware, test instructions, and a full circuit
diagram with a description. For many
boards you will also find sample code,
coding instructions, and application notes.
Datasheets are available on our website:
www.matrixtsl.com.
An E-blocks system