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DS3134
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Bit 6 / Sync Select Bit 0 (RSS0).
Bit 7 / Sync Select Bit 1 (RSS1).
These 2 bits select the mode in which each port is to be operated. Each port can be configured to accept
24, 32, 64, or 128 DS0 channels at an 8 kHz rate. These bits are ignored if the port has been configured
to operate in an unchannelized fashion (RUEN = 1).
00 = T1 Mode (24 DS0 channels & 193 RC clocks in between RS sync signals)
01 = E1 Mode (32 DS0 channels & 256 RC clocks in between RS sync signals)
10 = 4.096 MHz Mode (64 DS0 channels & 512 RC clocks in between RS sync signals)
11 = 8.192 MHz Mode (128 DS0 channels & 1024 RC clocks in between RS sync signals)
Bit 8 / Port 0 High Speed Mode (RP0(1)HS). If enabled, the Port 0(1) Layer State Machine logic is
defeated and RC0(1) and RD0(1) are routed to some dedicated high speed HDLC processing logic. Only
present in RP0CR and RP1CR. Bit 8 is not assigned in Ports 2 through 15.
0 = disabled
1 = enabled
Bit 9 / Unchannelized Enable (RUEN).
When enabled, this bit forces the port to operate in an
unchannelized fashion. When disabled, the port will operate in a channelized mode.
0 = channelized mode
1 = unchannelized mode
Bit 10 / Local Loopback Enable (LLB). This loopback routes transmit data back to the receive port. It
can be used in both channelized and unchannelized port operating modes, even on ports 0 & 1 operating
at speeds up to 52 MHz. See Figure 5.1A. In channelized applications, a per-channel loopback can be
realized by using the Channelized Local LoopBack (CLLB) function. See Section 5.3 for details on
CLLB.
0 = loopback disabled
1 = loopback enabled
Bit 12 / V.54 Time Out (VTO). This read only bit reports the real time status of the V.54 detector. It
will be set to a one when the V.54 detector has finished searching for the V.54 loop up pattern and has not
detected it. This indicates to the Host that the V.54 detector can now be used to search for the V.54 loop
up pattern on other HDLC channels and the Host can initiate this by configuring the RV54 bits in the
RP[n]CR register and then toggling the VRST control bit. See Section 5.4 for more details on how the
V.54 detector operates.
Bit 13 / V.54 Loopback (VLB). This read only bit reports the real time status of the V.54 detector. It
will be set to a one when the V.54 detector has verified that a V.54 loop up pattern has been seen. When
set, it will remain set until either the V.54 loop down pattern is seen or the V.54 detector is reset by the
Host (i.e. by toggling VRST). See Section 5.4 for more details on how the V.54 detector operates.
Bit 14 / Interrupt Enable for RCOFA (IERC).
0 = interrupt masked
1 = interrupt enabled