mt9075bpr1 Zarlink Semiconductor, mt9075bpr1 Datasheet - Page 33

• Manufacturer Part Number: mt9075bpr1
• Description: E1 Single Chip Transceiver With Liu
• Manufacturer: Zarlink Semiconductor

A-law Milliwatt
If the control bit ADSEQ is one (from master control page 02H - access control word), the A-law digital milliwatt
sequence (Table 10), defined by G.711, is available to be transmit on any combination of selected channels. The
channels are selected by setting bit 3 (TTST), in the Per Time Slot Control Word.
The same sequence is available to replace received data on any combination of DSTo channels. This is
accomplished by setting bit 2 (RRST) in the Per Time Slot Control Word for the corresponding channel.
Message Mode
The transmit data on any of the transmit channels may be sourced either from the equivalent DSTi channel or from
a dual port RAM programmed by the microport. The address of each dual port RAM memory location is uniquely
associated with a transmit channel number. When bit 7 (TXMSG) in the Per Time Slot Control Word for that channel
is set the transmit data for the channel is sourced from within the transmit message page dual port RAM (on page
0FH and 10H).
Receive data may also be read by the microprocessor port. The Rx message mode dual port RAMs (on page
11H and 12H) have a unique address associated with each incoming line channel. When the processor reads
any of the 32 memory locations, it reads the last byte received from the corresponding channel.
Alarms
The following alarms are detected by the receiver. Each may generate a maskable interrupt:
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•
•
•
•
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•
Remote Alarm Indication (RAI) - bit 3 (A) of the receive NFAS;
Alarm Indication Signal (AIS) - unframed all ones signal for at least a double frame (512 bits) or two double
frames (1024 bits);
Channel 16 Alarm Indication Signal - all ones signal in channel 16;
Auxiliary pattern - 101010... pattern for at least 512 bits;
Loss of Signal - a loss of signal condition occurs when the receive signal is detected with more than 127
consecutive zeros. A loss of signal condition will terminate when an average ones density of at least 12.5%
has been received over a period of 127 contiguous pulse positions starting with a pulse.
Remote Signalling Multiframe Alarm - bit 6 (Y-bit) of the multiframe alignment signal.
T1 - (T1 timer bit on page 03H address 12H) this status bit (and maskable interrupt) shall be high when a
signal that is not normal has been received for a minimum of 100 msec. This bit will be low when a normal
signal is being received.
Bit
1
0
0
0
0
1
1
1
1
Table 10 - A-Law Digital Milliwatt Pattern
Bit
2
0
0
0
0
0
0
0
0
Bit
Zarlink Semiconductor Inc.
3
1
1
1
1
1
1
1
1
MT9075B
Bit
4
1
0
0
1
1
0
0
1
33
Bit
5
0
0
0
0
0
0
0
0
Bit
6
1
0
0
1
1
0
0
1
Bit
7
0
0
0
0
0
0
0
0
Bit
8
0
1
1
0
0
1
1
0
Data Sheet