
MT9072
Data Sheet
93
Zarlink Semiconductor Inc.
14.2 E1 Maintenance and Alarms
Extensive maintenance and alarm generation and detection functions are provided on the MT9072. The following
table groups the registers for control and monitor of these functions.
14.2.1 E1 Error Insertion
Six types of error conditions can be inserted into the transmit PCM30 data stream through register control bits
located at address Y01. These error events include the bipolar violation errors (BVE), CRC-4 errors (CRCE), FAS
errors (FASE), NFAS errors (NFSE), payload (PERR) and a loss of signal error (LOSE). The LOSE function
overrides the HDB3 encoding function (no BPV are added). Also included are E1 and E2 error bit insertion on
frames 13 and 15. See the bit descriptions (control register address Y01) for additional details.
14.2.2 E1 Per Timeslot Control
There are 32 per timeslot control registers occupying a total of 32 unique addresses (Y90-YAF). Each register
controls a matching timeslot on the 32 transmit channels (onto the line) and the equivalent channel data on the
receive (DSTo) data. For example, register address Y91 of the first per timeslot control register contains program
control for transmit timeslot 1 and DSTo channel 1.
14.2.3 E1 Per Timeslot Looping
Any channel or combination of channels may be looped from transmit (sourced from DSTi) to receive (output on
DSTo) ST-BUS channels. When bit 4 (LTSL) in the Per Timeslot Control Word is set the data from the equivalent
transmit timeslot is looped back onto the equivalent receive channel.
Any channel or combination of channels may be looped from receive (sourced from the line data) to transmit
(output onto the line) channels. When bit 5 (RTSL) in the Per Timeslot Control Word is set the data from the
equivalent receive timeslot is looped back onto the equivalent transmit channel.
Register
Address
Register
Description
Y00
Alarm and Framing Control Register The TAIS and E bit errors and RAI can be set by this register.
Y01
Test Error and Loopback Control
Register
BPVE, CRCE,FASE, NFSE and E bit errors can be inserted.
Y05
CAS Control and Data Register
The Y bit can be used to send Remote Multiframe Alarm signal.
Y10
Synchronization and CRC-4
Remote Status
The bits of this register provide good receiver error status.
Y11
CRC-4 Timer and CRC-4 Local
Status
The CRC-4 errors are registered in Y11.
Y12
Alarms and MAS Status
This register provides AIS, RAI, LOSS status bits.
Y24
Sync, CRC-4 remote alarm, MAS
Latched Status Register
Latched version of receive CRC errors and synchronization loss
are available.
Y34
Sync, CRC-4 Remote Alarm, MAS
Interrupt status register
This register provides bits for interrupt generation for Y24 CRC
errors and synchronization loss functions.
Y44
Sync, CRC-4 Remote Alarm, MAS
Interrupt register mask
This register provides bits for interrupt mask register for Y34.
Table 47 - Registers Related to Maintenance and Alarms (E1)