
DS26401 Octal T1/E1/J1 Framer
18
Signal Name:
Signal Description:
Signal Type:
Pin can be configured to output either RCHBLK or RCHCLK. RCHBLK is a user programmable output that can be
forced high or low during any of the 24 T1 or 32 E1 channels. Synchronous with RCLK when the receive side elastic
store is disabled. Synchronous with RSYSCLK when the receive-side elastic store is enabled. Useful for blocking
clocks to a serial UART or LAPD controller in applications where not all channels are used such as fractional
service, 384kbps, service, 768kbps, or ISDN–PRI. Also useful for locating individual channels in drop-and-insert
applications, for external per-channel loopback, and for per-channel conditioning.
RCHBLK/CLK (1–8)
Receive Channel Block/Clock
Output
RCHCLK is a 192 kHz (T1) or 256kHz (E1) clock that pulses high during the LSB of each channel. Can also be
programmed to output a gated bit clock useful for fractional services. Synchronous with RCLK when the receive
side elastic store is disabled. Synchronous with RSYSCLK when the receive side elastic store is enabled. Useful for
parallel-to-serial conversion of channel data.
Signal Name:
RLOF/LOTC (1–8)
Signal Description:
Receive Loss of Frame/Loss of Transmit Clock
Signal Type:
Output
A dual function output that is controlled by the GCR1.5 control bit. This pin can be programmed to either toggle high
when the synchronizer is searching for the frame and multiframe or to toggle high if the TCLK pin has not been
toggled for approximately three clock periods.
Signal Name:
RLOS/RSIGF (1–8)
Signal Description:
Receive Loss of Signal/Receive Signaling Freeze
Signal Type:
Output
A dual function output that is controlled by the GCR2.3 control bit. This pin can be programmed to toggle high when
the framer detects a loss of signal condition, or when the signaling data is frozen via either automatic or manual
intervention. Used to alert downstream equipment of the condition.
Signal Name:
RF/RMSYNC (1–8)
Signal Description:
Receive Frame Sync/Receive Multiframe Sync
Signal Type:
Output
A dual function output controlled by the GCR2.2 control bit. RFSYNC is an extracted 8kHz pulse, one RCLK wide
that identifies frame boundaries. RMSYNC is an extracted pulse, one RCLK wide (elastic store disabled) or one
RSYSCLK wide (elastic store enabled), which identifies multiframe boundaries. When the receive elastic store is
enabled, the RMSYNC signal indicates the multiframe sync on the system (backplane) side of the e-store. In E1
mode, will indicate either the CRC4 or CAS multiframe as determined by the RSMS2 control bit at RIOCR.1