Matrix E-blocks Notice D'utilisation page 5

3. e
leCtrICal 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 con-
nect 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 con-
nected together a gender changer or In
Fig 8 - D-type connectors
sulation 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 interoperation 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 con-
nectors. 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.
On the photograph in Figure 9 you can clearly
see the red power wires linking the E-blocks
together. This design also routes 14V from the
Multiprogrammer to the Proto board.
Fig 9 - Example E-blocks system
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 pro-
grammer many times.
Some E-blocks boards
may have other com-
ponents 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 web site: www.matrixmultimedia.com.
Fig 10
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