Datasheet

DS26521 Single T1/E1/J1 Transceiver
205 of 258
Register Name:
LMCR
Register Description:
LIU Maintenance Control Register
Register Address:
1002h
Bit # 7 6 5 4 3 2 1 0
Name TAIS ATAIS LLB ALB RLB TPDE RPDE TE
Default 0 0 0 0 0 0 0 0
Bit 7: Transmit AIS (TAIS). Alarm Indication Signal (AIS) is sent using MCLK as the reference clock. The transmit
data coming from the framer is ignored.
0 = TAIS is disabled.
1 = Output an unframed all-ones pattern (AIS) at TTIP and TRING.
Bit 6: Automatic Transmit AIS (ATAIS).
0 = ATAIS is disabled.
1 = Automatically transmit AIS on the occurrence of an LIU LOS.
Bit 5: Local Loopback (LLB). See Section 8.11.5.2 for operational details.
0 = LLB is disabled.
1 = LLB is enabled.
Bit 4: Analog Loopback (ALB). See Section
8.11.5.1 for operational details.
0 = ALB is disabled.
1 = ALB is enabled.
Bit 3: Remote Loopback (RLB). See Section 8.11.5.3 for operational details.
0 = Remote loopback is disabled.
1 = Remote loopback is enabled.
In this loopback, received data passes all the way through the receive LIU and is then transmitted back
through the transmit side of the LIU. Data will continue to pass through the receive-side framer of the
DS26521 as it would normally and the data from the transmit side of the framer will be ignored.
Bit 2: Transmit Power-Down Enable (TPDE).
0 = Transmitter power enabled.
1 = Transmitter powered down. TTIP/TRING outputs are high impedance.
Bit 1: Receiver Power-Down Enable (RPDE).
0 = Receiver power enabled.
1 = Receiver powered down.
Bit 0: Transmit Enable (TE). This function is overridden by the TXENABLE pin.
0 = TTIP/TRING outputs are high impedance.
1 = TTIP/TRING outputs enabled.