PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 104

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

Semiconductor Group
Figure 43
Before starting a transmission, the microprocessor should verify that the transmitter is
inactive, i.e. that a possible previous transmission has been terminated. This is indicated
by a "0" in MOSR:MAC, the Monitor Channel Active status bit.
To enable interrupts for the transmitter the MOCR:MXE bit must be set to "1" (For details
see "Monitor-Channel Interrupt Logic", page 209). After having written the Monitor Data
Transmit (MOX) register, the microprocessor sets the Monitor Transmit Control bit MXC
to "1". This enables the MX bit to go active ("0"), indicating the presence of valid Monitor
data (contents of MOX) in the corresponding frame. As a result, the receiving device
stores the Monitor byte in its Monitor Receive (MOR) register and generates an MDR
interrupt status.
MOX
MOX = DATA1
MOX
=
MXC
MAC
MDA Int.
MDA Int.
MDA Int.
MXE = 1
MXC = 1
MAC
DATA2
=
Monitor Channel Protocol
ADR
=
=
P
=
0
0
1
FF
FF
ADR
ADR
DATA1
DATA1
DATA1
DATA1
DATA2
DATA2
DATA2
DATA2
FF
FF
FF
FF
MON
Transmitter
104
MX
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Receiver
MR
1
1
1
0
0
0
1
0
0
0
1
0
0
0
1
1
Operational Description
125 s
Data Sheet 01.99
MRE=
MDR Int.
RD
MRC
MDR Int.
RD
MDR Int.
RD MOR (= DATA2)
MER Int.
MRC = 0
ITD08119
MOR
MOR
PEB 2091
P
PEF 2091
= 1
1
(= ADR)
(=
DATA1)