
XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.1
PRELIMINARY
179
7.2.1
The DS1 Receive Overhead Output Interface Block allows an external device to be the consumer of the Facili-
ty Data Link (FDL) bits in ESF framing format mode, Signaling Framing (Fs) bits in the SLC96 and N framing
format mode and Remote Signaling (R) bit in T1DM framing format mode This interface provides interface sig-
nals and required interface timing to shift out proper data link information at proper time.
The Receive Overhead Output Interface for a given Framer consists of two signals.
RxOHClk_n: The Receive Overhead Output Interface Clock Output signal
RxOH_n: The Receive Overhead Output Interface Output signal.
The Receive Overhead Output Interface Clock Output pin (RxOHCLK_n) generates a rising clock edge for
each data link bit position according to configuration of the framer. The data link bits extracted from the incom-
ing T1 frames are outputted from the Receive Overhead Output Interface Output pin (RxOH_n) at the rising
edge of RxOHClk_n. The Data Link equipment should sample and latch the data link bits at the falling edge of
RxOHClk_n.
The figure below shows block diagram of the Receive Overhead Output Interface of XRT86L30.
Description of the DS1 Receive Overhead Output Interface Block
7.2.2
Data Link (FDL) bits in ESF framing format mode
The FDL bits in ESF framing format mode can be extracted to:
DS1 Receive Overhead Output Interface Block
DS1 Receive HDLC Controller
DS1 Receive Serial Output Interface.
The Receive Data Link Source Select bits of the Receive Data Link Select Register (RDLSR) controls the ex-
traction of FDL bits in ESF framing format mode. The table below shows configuration of the Receive Data Link
Source Select bits of the Receive Data Link Select Register (RDLSR).
Configure the DS1 Receive Overhead Output Interface module as destination of the Facility
F
IGURE
40. B
LOCK
D
IAGRAM
OF
THE
DS1 R
ECEIVE
O
VERHEAD
O
UTPUT
I
NTERFACE
OF
XRT86L30
RECEIVE DATA LINK SELECT REGISTER (TDLSR) (ADDRESS = 0X010AH)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
1-0
Receive Data Link
Destination Select
R/W
00 - The extracted Facility Data Link bits are stored in either the LAPD controller
or the SLC96 buffer. At the same time, the extracted Facility Data Link bits are
outputted from the framer through the Receive Serial Data Output Interface via
the RxSer_n pins.
01 - The extracted Facility Data Link bits are outputted from the framer through
the Receive Serial Data Output Interface via the RxSer_n pins.
10 - The extracted Facility Data Link bits are outputted from the framer through
the Receive Overhead Output Interface via the RxOH_n pins. At the same time,
the extracted Facility Data Link bits are outputted from the framer through the
Receive Serial Data Output Interface via the RxSer_n pins.
11 - The Facility Data Link bits are forced to one by the framer.
Receive
Overhead Output
Interface
RxOH_n
RxOHClk_n
From Receive
Framer Block