DS3181 Maxim Integrated Products, DS3181 Datasheet - Page 121

• Manufacturer Part Number: DS3181
• Description: Network Controller & Processor ICs DS3-E3 ATM-Packet PH Y with Built-in Line
• Manufacturer: Maxim Integrated Products

Specifications of DS3181

• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 44.736 Mbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 280 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Package / Case: TEBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 10-19
Table 10-19. Payload (Downstream) AIS Enable Modes
10.5.4 Loop Timing Mode
Loop timing mode is enabled by setting the PORT.CR3.LOOPT bit. This mode replaces the clock from the TCLKIn
pin with the internal receive clock from either the RLCLKn pin if the RX LIU is disabled, or the recovered clock from
the RX LIU if it is enabled. The loop timing mode can be activated in any framing or line interface mode.
10.5.5 HDLC Overhead Controller
There is a single HDLC controller for use in line maintenance protocols. The DS3, E3 and PLCP framers share the
same HDLC controller. Since the PLCP and DS3 or E3 framers can potentially use the HDLC controller at the
same time, there is a select bit in the port control register to chose which one uses the HDLC controller
(PORT.CR1.HDSEL). The port that does not get access to the HDLC controller will transmit all ones in the
overhead bits that the HDLC controller would connect to. The external overhead ports can be used to connect to
an external HDLC controller if both framers need the function.
The data signal to the receive HDLC controller will be forced to a one while still being clocked when the framer
(DS3, E3, or PLCP), to which the HDLC is connected, detects LOF or AIS. Forcing the data signal to all ones will
cause an HDLC packet abort if the data started to look like a packet instead of allowing a bad, and possibly very
long, HDLC packet.
10.5.6 Trail Trace
There is a single Trail Trace controller for use in line maintenance protocols. The E3-G.832 and PLCP framers can
use the trail trace controller and it is shared automatically since the E3-G.832 and PLCP framing cannot be
enabled at the same time.
10.5.7 BERT
There is a Bit Error Rate Test (BERT) circuit for each port for use in generating and detecting test signals in the
payload bits. The BERT can generate and detect PRBS patterns up to 2^32-1 bits as well as repeating patterns up
to 32 bits long. The generated BERT signal replaces the cells or packets from the system interface when the BERT
is enabled by setting the PORT.CR1.BENA.
The cells or packets from the system interface will still be processed using the same bit rate as when the BERT
was not enabled. Any transmit cells will be simply discarded when the BERT is enabled, and any cells or packets
on the line interface will be processed and sent to the system bus when the BERT is enabled. The TDENn and
RDENn pins will still be active but the data on the TSERn pin will be discarded when the BERT is enabled.
PORT.CR1
PAIS[2:0]
000
001
010
011
100
101
110
111
lists the PAIS decodes for various payload AIS enable modes.
Always
When LLB (no DLB) active
When PLB active
When LLB(no DLB) or PLB active
When LOS (no DLB) active
When OOF active
When OOF, LOS. LLB (no DLB), or
PLB active
Never
WHEN AIS IS SENT
AIS CODE
121
none
UA1
UA1
UA1
UA1
UA1
UA1
UA1