DS2182A T1 Line Monitor Chip
Table 1. Pin Description
PIN
NAME
TYPE
FUNCTION
1
INT
O
Receive Alarm Interrupt. Flags host controller during alarm conditions. Active
low; open-drain output.
2
SDI
I Serial Data In. Data for on-board registers. Sampled on rising edge of SCLK.
Serial Data Out. Control and status information from on-board registers.
3
SDO
O Updated on falling edge of SCLK; tri-stated during serial port write or when CS
is high.
4
CS
I Chip Select. Must be low to read or write the serial port.
5
6, 13
7
8
9
SCLK
N.C.
RYEL
RLINK
RLCLK
I Serial Data Clock. Used to read or write the serial port registers.
—
No Connect. No internal connection. This pin can be connected to either VSS
or VDD, or it can be floated.
O
Receive Yellow Alarm. Transitions high when a yellow alarm detected; goes
low when the alarm clears.
Receive Link Data. Updated with extracted FDL data one RCLK before start
O of odd frames (193E) and held until next update. Updated with extracted S-bit
data one RCLK before start of even frames (193S) and held until next update.
O Receive Link Clock. 4kHz demand clock for RLINK
10
RCLK
I Receive Clock. 1.544MHz primary clock
11
RCHCLK
O
Receive Channel Clock. 192kHz clock; identifies timeslot (channel)
boundaries
12
RSER
O
Receive Serial Data. Received NRZ serial data; updated on rising edges of
RCLK
15
RFSYNC
O
Receive Frame Sync. Extracted 8kHz clock, one RCLK wide; F-bit position in
each frame
16
RMSYNC
O
Receive Multiframe Sync. Extracted multiframe sync; positive-going edge
indicates start of multiframe; 50% duty cycle
Receive ABCD Signaling. Extracted signaling data output; valid for each
17
RABCD
O channel in signaling frames. In non-signaling frames, RABCD outputs the LSB
of each channel word.
18
RSIGFR
O
Receive Signaling Frame. High during signaling frames; low during non-
signaling frames (and during resync)
19
RSIGSEL
O
Receive Signaling Select. In 193E framing, a .667kHz clock that identifies
signaling frames A and C; a 1.33kHz clock in 193S
21
RST
I
Reset. A high-low transition clears all internal registers and resets counters. A
high-low-high transition initiates a resync.
22
RPOS
23
RNEG
I
Receive Bipolar Data Inputs. Sampled on falling of RCLK. Connect together
to receive NRZ data and disable bipolar violation monitoring circuitry.
24
RCL
25
RBV
O
Receive Carrier Loss. High if 192 consecutive 0’s appear at RPOS and
RNEG; goes low upon seeing 12.5% 1’s density.
O
Receive Bipolar Violation. High during accused bit time at RSER. If bipolar
violation detected, low otherwise.
26
RFER
O
Receive Frame Error. High during F-bit time when FT or FS errors occur
(193S), or when FPS or CRC errors occur (193E). Low during resync.
27
RLOS
O
Receive Loss-of-Sync. Indicates sync status; high when internal resync is in
progress, low otherwise.
2 of 26