PEB2465 SIEMENS [Siemens Semiconductor Group], PEB2465 Datasheet - Page 70

• Manufacturer Part Number: PEB2465
• Description: Four Channel Codec Filter
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Semiconductor Group
10.1.2 Monitor Handshake Procedure
The monitor channel works in 3 states
– idle state:
– sending state:
– acknowledging: MR-bit is set to active (set to ‘0’) by the Monitor-receiver, together
A start of transmission is initiated by a Monitor-transmitter in sending out an active
MX-bit together with the first byte of data (the address of the receiver) to be transmitted
in the Monitor-channel.
This state remains until the addressed Monitor-Receiver acknowledges the received
data by sending out an active MR-bit, which means that the data-transmission is
repeated each 125
Monitor-transmitter evaluates the MR-bit.
Flow control, means in the form of transmission delay, can only take place when the
transmitters MX and the receivers MR bit are in active state.
Since the receiver is able to receive the monitor data at least twice (in two consecutive
frames), it is able to check for data errors. If two different bytes are received the receiver
will wait for the receipt of two identical successive bytes (last look function).
A collision resolution mechanism (check if another device is trying to send data during
the same time) is implemented in the transmitter. This is done by looking for the inactive
(‘1’) phase of the MX-bit and making a per bit collision check on the transmitted monitor
data (check if transmitted ‘1’s are on DU/DD-line; DU/DD-line are open-drain lines).
Any abort leads to a reset of the SICOFI-4 command stack, the device is ready to receive
new commands.
To obtain a maximum speed data transfer, the transmitter anticipates the falling edge of
the receivers acknowledgment.
Due to the inherent programming structure, duplex operation is not possible. It is not
allowed to send any data to the SICOFI-4, while transmission is active.
A pair of inactive (set to ‘1’) MR- and MX-bits during two or more
consecutive frames: End of Message (EOM)
MX-bit is activated (set to ‘0’) by the Monitor-transmitter, together
with data-bytes (can be changed) on the Monitor-channel
with a data-byte remaining in the Monitor-channel.
s frame (minimum is one repetition). During this time the
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PEB 2465
Appendix
02.97