TC1796
Peripheral Units (Vol. 2 of 2)
Micro Link Interface (MLI)
User’s Manual
23-46
V2.0, 2007-07
MLI, V2.0
Receiving Controller
The MLI receiver operates with an address prediction method equivalent to the MLI
transmitter. This means that after receiving at least two consecutive Write Offset and
Data Frames and/or Discrete Read Frames that include address information, the MLI
receiver is able to follow the address prediction method used by the MLI transmitter.
Each received offset is compared in the MLI receiver with the offset of the previously
received frame of the same pipe. The result of this comparison is stored in two’s
complement representation in RPxSTATR.AP (limited 9 bits).
If an optimized frame is received by the MLI receiver, it calculates the next address by
adding the value stored in RPxSTATR.AP to the contents of the receiver address
register RADRR.
In case of a Write Offset and Data Frame or a Discrete Read Frame (m offset bits), the
receiver address registers RADRR and RPxBAR are always loaded with an updated
address. This address is calculated by replacing the lowest m bit positions in RPxBAR
with the received offset value. In this case, the address delta value stored in
RPxSTATR.AP is not taken into account. The programmed size of the Remote Window
and the number m of offset bits are given by RPxSTATR.BS. The bit positions
RPxBAR[31:m] are kept constant, whereas the bit positions RPxBAR[m-1:0] are
replaced.
23.2.2.4 Automatic Data Mode
The MLI module supports automatic data transfers for read or Write Frames without any
CPU load in the receiving controller. This features is based on a move engine block
providing the data, the complete address and the data width to an associated bus master
on the system bus (see
). Depending on the implementation, this bus master
can be capable of executing the requested data move operations autonomously. The
Automatic Data Mode in the receiving controller can be enabled (RCR.MOD = 1) or
disabled (RCR.MOD = 0) by software on receiving side or a Command Frame sent by
the transmitting controller.
If the Automatic Data Mode is disabled, the receiving controller software has to execute
the requested data transfers.
Additionally to the global enable/disable of the automatic mode by RCR.MOD, it is
possible to individually exclude address ranges from automatic data transfer by an
access protection scheme. The definition of the address ranges depend on the product
and has been introduced to support the protection of critical data or modules.
Note: If a device contains the MLI move engine block as the only bus master, automatic
mode has to be selected to allow transfers. This could be the case for external
peripheral devices without own CPU.