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DS2154
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5.4
FAS Error Counter
FAS Count Register 1 (FASCR1) is the most significant
word and FASCR2 is the least significant word of a
12–bit counter that records word errors in the Frame
Alignment Signal in timeslot 0. This counter is disabled
during loss of synchronization conditions, (RLOS = 1).
Since the maximum FAS word error count in a one
second period is 4000, this counter cannot saturate.
FASCR1: FAS BIT COUNT REGISTER 1 (Address=02 Hex)
FASCR2: FAS BIT COUNT REGISTER 2 (Address=04 Hex)
(MSB)
(LSB)
FAS11
FAS10
FAS9
FAS8
FAS7
FAS6
(note 2)
(note 2)
FAS5
FAS4
FAS3
FAS2
FAS1
FAS0
(note 1)
(note 1)
SYMBOL
POSITION
NAME AND DESCRIPTION
FAS11
FASCR1.7
MSB of the 12–bit FAS error count.
FAS0
FASCR2.2
LSB of the 12–bit FAS error count.
NOTES:
1. The lower two bits of FASCR1 at address 02 are the most significant bits of the 10–bit CRC4 error counter.
2. The lower two bits of FASCR2 at address 04 are the most significant bits of the 10–bit E–bit counter.
6.0
DS0 MONITORING FUNCTION
The DS2154 has the ability to monitor one DS0 64 Kbps
channel in the transmit direction and one DS0 channel
in the receive direction at the same time. In the transmit
direction the user will determine which channel is to be
monitored by properly setting the TCM0 to TCM4 bits in
the CCR4 register. In the receive direction, the RCM0 to
RCM4 bits in the CCR5 register need to be properly set.
The DS0 channel pointed to by the TCM0 to TCM4 bits
will appear in the Transmit DS0 Monitor (TDS0M) regis-
ter and the DS0 channel pointed to by the RCM0 to
RCM4 bits will appear in the Receive (RDS0M) register.
The TCM4 to TCM0 and RCM4 to RCM0 bits should be
programmed with the decimal decode of the appropriate
E1 channel. For example, if DS0 Channel 6 (timeslot 5)
in the transmit direction and DS0 Channel 15 (timeslot
14) in the receive direction needed to be monitored,
then the following values would be programmed into
CCR4 and CCR5:
TCM4=0
RCM4=0
TCM3=0
RCM3=1
TCM2=1
RCM2=1
TCM1=0
RCM1=1
TCM0=1
RCM0=0
CCR4: DS0 MONITORING FUNCTION (Address=A8 Hex)
[repeated here from section 3 for convenience]
(MSB)
(LSB)
RLB
LLB
LIAIS
TCM4
TCM3
TCM2
TCM1
TCM0
SYMBOL
POSITION
NAME AND DESCRIPTION
RLB
CCR4.7
Remote Loopback. See Section 3 for details.
LLB
CCR4.6
Local Loopback. See Section 3 for details.
LIAIS
CCR4.5
Line Interface AIS Generation Enable. See Section 3 for details.
TCM4
CCR4.4
Transmit Channel Monitor Bit 4. MSB of a channel decode that deter-
mines which transmit DS0 channel data will appear in the TDS0M register.
TCM3
CCR4.3
Transmit Channel Monitor Bit 3.
FASCR1
FASCR2