peb20550 Infineon Technologies Corporation, peb20550 Datasheet - Page 206

• Manufacturer Part Number: peb20550
• Description: Extended Pcm Interface Controller
• Manufacturer: Infineon Technologies Corporation

PEB 2055
PEF 2055
Application Hints
Search For Active Monitor Channels Command
In IOM-2 applications the monitor channel is sometimes used for low speed data
transfers over the S and Q channels of an S interface or over the EOC channel of a U
(2B1Q) interface. The layer-1 transceivers (SBCX PEB 2081, IEC-Q PEB 2091) may
then, upon reception of a new message, start a monitor channel communication with the
EPIC.
For those applications where a slave device initiates an MF channel transfer, the EPIC
has implemented the “Search For Active Monitor Channels Command”.
The active handshake protocol (OMDR:MFPS = 1) must be selected for this function.
When the “MF Search On” command (CMDR:MFSO = 1) is executed, the EPIC
searches for active handshake bits (MX) on all upstream monitor channels. As soon as
an active channel is found, an ISTA:MAC interrupt is generated, the search is stopped,
and the address of this channel is stored in MFAIR. The P can then copy the value of
MFAIR to MFSAR in order to point the MF handler to that particular channel. With an
empty MFFIFO the transmit + receive same time slot command can be executed to
initiate the reception of the monitor message. The EPIC will then autonomously
acknowledge each received byte and report the end of the transfer by an ISTA:MFFI
interrupt. The P can read the message from the MFFIFO and, if required, execute a
new MF Search command.
Note: The search should only be started when no receive transfer is in operation,
otherwise each received byte will lead to the ISTA:MAC interrupt.
Once started, the search for active monitor channels can only be stopped when such a
channel has been found or when the Control Memory is reset or initialized
(OMDR:OMS0 = 0).
Semiconductor Group
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