TC1796
Peripheral Units (Vol. 2 of 2)
Micro Link Interface (MLI)
User’s Manual
23-20
V2.0, 2007-07
MLI, V2.0
with propagation delays in the range of some shift clock cycles and to avoid the closed-
loop delay limitations of an SPI connection.
In a full handshake, each edge of the handshake signals has a defined meaning and the
sequence of edges is clearly specified.
As a result, the propagation delays do not directly limit the MLI baud rate. Therefore, the
points in time when a signal is generated, when it is visible on the physical interface line,
or when it is evaluated have to be considered independently. This is done by defining 3
different names for a signal, referring to the 3 significant locations:
•
The place where it is generated, also in relation to the generation clock edge
•
The physical interface line where it can be observed
•
The place where it is evaluated, also in relation to the evaluation clock edge
If a Local Controller should be connected to more than one Remote Controller, the
transmitter signals CLK and DATA can be used as broadcast signals (parallel connection
to the Remote Controllers), whereas the handshake signals VALID and READY have to
be established as independent signal pairs for each device. As a result, a Local
Controller only needs one CLK and one DATA output, but an individual set of READY
and VALID handshake signals for each Remote Controller. Please note that Read
Frames and Answer Frames are based on an established connection between a Local
and a Remote Controller (because the Answer Frame is the only frame sent back to the
Local Controller). Therefore, switching between several Remote Controllers can only be
done while no read request is pending in the Local Controller. If no Read Frames are
used by the Local Controller, frames can be sent out in parallel to all Remote Controllers
if their READY signals are all respected.
If a Remote Controller should be connected to several Local Controllers, it may have
several DATA and CLK inputs in addition to the READY-VALID signal sets. Please note
that an active switching of a Remote Controller between several Local Controllers
requires that all Local Controllers have the information which connection is active.
In any case, switching between Local and Remote Controllers is not allowed while frame
transmission is in progress.