PEF82912FV1.4 Infineon Technologies, PEF82912FV1.4 Datasheet - Page 59

• Manufacturer Part Number: PEF82912FV1.4
• Description: ISDN Interface ISDN
• Manufacturer: Infineon Technologies

Specifications of PEF82912FV1.4

• Mounting Style: SMD/SMT
• Package / Case: MQFP-64
• Lead Free Status / Rohs Status: Details

In addition, it enables other MONITOR channel interrupts by setting MONITOR Interrupt
Enable (MIE) to ’1’.
As a result, the first MONITOR byte is acknowledged by the receiving device setting the
MR bit to ’0’. This causes a MONITOR Data Acknowledge MDA interrupt status at the
transmitter.
A new MONITOR data byte can now be written by the microprocessor in MOX. The MX
bit is still in the active (0) state. The transmitter indicates a new byte in the MONITOR
channel by returning the MX bit active after sending it once in the inactive state. As a
result, the receiver stores the MONITOR byte in MOR and generates a new MDR
interrupt status. When the microprocessor has read the MOR register, the receiver
acknowledges the data by returning the MR bit active after sending it once in the inactive
state. This in turn causes the transmitter to generate a MDA interrupt status.
This "MDA interrupt – write data – MDR interrupt – read data – MDA interrupt"
handshake is repeated as long as the transmitter has data to send. Note that the
MONITOR channel protocol imposes no maximum reaction times to the microprocessor.
When the last byte has been acknowledged by the receiver (MDA interrupt status), the
microprocessor sets the MONITOR Transmit Control bit MXC to ’0’. This enforces an
inactive (’1’) state in the MX bit. Two frames of MX inactive signifies the end of a
message. Thus, a MONITOR Channel End of Reception MER interrupt status is
generated by the receiver when the MX bit is received in the inactive state in two
consecutive frames. As a result, the microprocessor sets the MR control bit MRC to 0,
which in turn enforces an inactive state in the MR bit. This marks the end of the
transmission, making the MONITOR Channel Active MAC bit return to ’0’.
During a transmission process, it is possible for the receiver to ask a transmission to be
aborted by sending an inactive MR bit value in two consecutive frames. This is effected
by the microprocessor writing the MR control bit MRC to ’0’. An aborted transmission is
indicated by a MONITOR Channel Data Abort MAB interrupt status at the transmitter.
The MONITOR transfer protocol rules are summarized in the following section
• A pair of MX and MR in the inactive state for two or more consecutive frames indicates
• A start of a transmission is initiated by the transmitter by setting the MXC bit to ’1’
• The internal MX, MR control indicates or acknowledges a new byte in the MON slot
• Two frames with the MR-bit set to inactive indicate a receiver request for abort.
• The transmitter can delay a transmission sequence by sending the same byte
Data Sheet
an idle state or an end of transmission.
enabling the internal MX control. The receiver acknowledges the received first byte by
setting the MR control bit to ’1’ enabling the internal MR control.
by toggling MX, MR from the active to the inactive state for one frame.
continuously. In that case the MX-bit remains active in the IOM -2 frame following the
first byte occurrence. Delaying a transmission sequence is only possible while the
receiver MR-bit and the transmitter MX-bit are active.
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Functional Description
PEF 82912/82913
2001-03-30