Rainbow Electronics DS2154 - Manual (Page 21)

DS2154
031197 21/69
RHDB3 CCR1.2 Receive HDB3 Enable.
0=HDB3 disabled
1=HDB3 enabled
RG802 CCR1.1 Receive G.802 Enable. See Section 13 for details.
0=do not force RCHBLK high during bit 1 of timeslot 26
1=force RCHBLK high during bit 1 of timeslot 26
RCRC4 CCR1.0 Receive CRC4 Enable.
0=CRC4 disabled
1=CRC4 enabled
FRAMER LOOPBACK
When CCR1.7 is set to a one, the DS2154 will enter a
Framer LoopBack (FLB) mode. See Figure 1–1 for
more details. This loopback is useful in testing and
debugging applications. In FLB, the DS2154 will loop
data from the transmit side back to the receive side.
When FLB is enabled, the following will occur:
1. Data will be transmitted as normal at TPOSO and
TNEGO.
2. Data input via RPOSI and RNEGI will be ignored.
3. The RCLK output will be replaced with the TCLK
input.
CCR2: COMMON CONTROL REGISTER 2 (Address=1A Hex)
(MSB) (LSB)
ECUS VCRFS AAIS ARA RSERC LOTCMC RFF RFE
SYMBOL POSITION NAME AND DESCRIPTION
ECUS CCR2.7 Error Counter Update Select. See Section 5 for details.
0=update error counters once a second
1=update error counters every 62.5 ms (500 frames)
VCRFS CCR2.6 VCR Function Select. See Section 5 for details.
0=count BiPolar Violations (BPVs)
1=count Code Violations (CVs)
AAIS CCR2.5 Automatic AIS Generation.
0=disabled
1=enabled
ARA CCR2.4 Automatic Remote Alarm Generation.
0=disabled
1=enabled
RSERC CCR2.3 RSER Control.
0=allow RSER to output data as received under all conditions
1=force RSER to one under loss of frame alignment conditions
LOTCMC CCR2.2 Loss of Transmit Clock Mux Control. Determines whether the transmit
side formatter should switch to the ever present RCLKO if the TCLK should
fail to transition (see Figure 1–1).
0=do not switch to RCLKO if TCLK stops
1=switch to RCLKO if TCLK stops
RFF CCR2.1 Receive Force Freeze. Freezes receive side signaling at RSIG (and
RSER if CCR3.3=1); will override Receive Freeze Enable (RFE). See Sec-
tion 7–2 for details.
0=do not force a freeze event
1=force a freeze event