DS2152
CCR5: COMMON CONTROL REGISTER 5 (Address=19 Hex)
(MSB)
(LSB)
TCM0
TJC
LLB
LIAIS
TCM4
TCM3
TCM2
TCM1
SYMBOL
POSITION NAME AND DESCRIPTION
TJC
LLB
CCR5.7
CCR5.6
CCR5.5
Transmit Japanese CRC6 Enable.
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)
1 = use Japanese standard JT-G704 CRC6 calculation
Local Loopback.
0 = loopback disabled
1 = loopback enabled
LIAIS
Line Interface AIS Generation Enable. See Figure 1-1 for
details.
0 = allow normal data from TPOSI/TNEGI to be transmitted at
TTIP and TRING
1 = force unframed all 1s to be transmitted at TTIP and TRING
TCM4
CCR5.4
Transmit Channel Monitor Bit 4. MSB of a channel decode
that determines which transmit channel data will appear in the
TDS0M register. See Section 6 for details.
TCM3
TCM2
TCM1
TCM0
CCR5.3
CCR5.2
CCR5.1
CCR5.0
Transmit Channel Monitor Bit 3.
Transmit Channel Monitor Bit 2.
Transmit Channel Monitor Bit 1.
Transmit Channel Monitor Bit 0. LSB of the channel decode.
Local Loopback
When CCR5.6 is set to a 1, the DS2152 will be forced into Local LoopBack (LLB). In this loopback, data
will continue to be transmitted as normal through the transmit side of the DS2152 (unless LIAIS = 1).
Data being received at RTIP and RRING will be replaced with the data being transmitted. Data in this
loopback will pass through the jitter attenuator. Please see Figure 1-1 for more details. Please note that it
is not acceptable to have RCLKO tied to TCLKI during this loopback because this will cause an unstable
condition. Also it is recommended that the jitter attenuator be placed on the transmit side during this
loopback.
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DALLAS [ DALLAS SEMICONDUCTOR ]
