Table of Contents
Advertisement
SYMBOL
POSITION NAME AND DESCRIPTION
LLB
CCR4.6
LIAIS
CCR4.5
TCM4
CCR4.4
TCM3
CCR4.3
TCM2
CCR4.2
TCM1
CCR4.1
TCM0
CCR4.0
6.4 Remote Loopback
When CCR4.7 is set to a one, the SCT will be forced into Remote LoopBack (RLB). In this loopback,
data input via the RPOSI and RNEGI pins will be transmitted back to the TPOSO and TNEGO pins. Data
will continue to pass through the receive side framer of the SCT as it would normally and the data from
the transmit side formatter will be ignored. Please see Figure 3-1 for more details.
6.5 Local Loopback
When CCR4.6 is set to a one, the SCT will be forced into Local LoopBack (LLB). In this loopback, data
will continue to be transmitted as normal through the transmit side of the SCT. 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 3-1 for more details.
CCR5: COMMON CONTROL REGISTER 5 (Address=AA Hex)
(MSB)
LIRST
RESA
SYMBOL
POSITION NAME AND DESCRIPTION
LIRST
CCR5.7
RESA
CCR5.6
Local Loopback.
0 = loopback disabled
1 = loopback enabled
Line Interface AIS Generation Enable.
0 = allow normal data from TPOSI/TNEGI to be transmitted at TTIP and
TRING
1 = force unframed all ones to be transmitted at TTIP and TRING at the
MCLK rate
Transmit Channel Monitor Bit 4. MSB of a channel decode that
determines which transmit channel data will appear in the TDS0M
register. See Section 9 for details.
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.
TESA
RCM4
Line Interface Reset. Setting this bit from a zero to a one will initiate an
internal reset that affects the clock recovery state machine and jitter
attenuator. Normally this bit is only toggled on power–up. Must be
cleared and set again for a subsequent reset.
Receive Elastic Store Align. Setting this bit from a zero to a one may
force the receive elastic store's write/read pointers to a minim separation
of half a frame. No action will be taken if the pointer separation is
already greater or equal to half a frame. If pointer separation is less then
half a frame, the command will be executed and data will be disrupted.
37 of 117
RCM3
RCM2
DS21354 & DS21554
(LSB)
RCM1
RCM0
Advertisement
Table of Contents
