DS26514GN+ Maxim Integrated Products, DS26514GN+ Datasheet - Page 66

• Manufacturer Part Number: DS26514GN+
• Description: IC TXRX T1/E1/J1 4PORT 256-CSBGA
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of DS26514GN+

• Number Of Drivers/receivers: 4/4
• Protocol: Ethernet
• Voltage - Supply: 3.14 V ~ 3.47 V
• Mounting Type: Surface Mount
• Package / Case: 256-CSBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.9.8.2 Receive RAI
Table 9-27
Table 9-27. Registers Related to Receive RAI (Yellow Alarm)
Note: The addresses shown above are for Framer 1. Addresses for Framers 2 to 4 can be calculated using the following: Framer n = (Framer 1
address + (n - 1) x 200hex), where n = 2 to 4 for Framers 2 to 4.
9.9.8.3 E1 Automatic Alarm Generation
The device can be programmed to automatically transmit AIS or remote alarm. When automatic AIS generation is
enabled (E1.TCR2.AAIS = 1), the device monitors the receive-side framer to determine if any of the following
conditions are present/loss of receive frame synchronization, AIS alarm (all ones) reception, or loss of receive
carrier (or signal). If any one (or more) of the above conditions is present, then the framer will either force an AIS.
When automatic RAI generation is enabled (E1.TCR2.ARA = 1), the framer monitors the receive side to determine
if any of the following conditions are present/ loss of receive frame synchronization, AIS alarm (all ones) reception,
or loss of receive carrier (or signal) or if CRC-4 multiframe synchronization cannot be found within 128ms of FAS
synchronization (if CRC-4 is enabled). If any one (or more) of the above conditions is present, then the framer will
transmit a RAI alarm. RAI generation conforms to ETS 300 011 and ITU-T G.706 specifications.
Note: It is an illegal state to have both automatic AIS generation and automatic remote alarm generation enabled
at the same time.
9.9.8.4 Receive AIS-CI and RAI-CI Detection
AIS-CI is a repetitive pattern of 1.26 seconds. It consists of 1.11 seconds of an unframed all-ones pattern and 0.15
seconds of all ones modified by the AIS-CI signature. The AIS-CI signature is a repetitive pattern 6176 bits in
length in which, if the first bit is numbered bit 0, bits 3088, 3474 and 5790 are logical zeros and all other bits in the
pattern are logical ones (T1.403). AIS-CI is an unframed pattern, so it is defined for all T1 framing formats. The
RAIS-CI bit is set when the AIS-CI pattern has been detected and RAIS (RRTS1.2) is set. RAIS-CI is a latched bit
that should be cleared by the host when read. RAIS-CI will continue to set approximately every 1.2 seconds that
the condition is present. The host will need to ‘poll’ the bit, in conjunction with the normal AIS indicators to
determine when the condition has cleared.
RAI-CI is a repetitive pattern within the ESF data link with a period of 1.08 seconds. It consists of sequentially
interleaving 0.99 seconds of “00000000 11111111” (right-to-left ) with 90 ms of “00111110 11111111”. The RRAI-
CI bit is set when a bit oriented code of “00111110 11111111” is detected while RRAI (RRTS1.3) is set. The RRAI-
CI detector uses the receive BOC filter bits (RBF0 and RBF1) located in RBOCC to determine the integration time
for RAI-CI detection. Like RAIS-CI, the RRAI-CI bit is latched and should be cleared by the host when read. RRAI-
CI will continue to set approximately every 1.1 seconds that the condition is present. The host will need to “poll” the
bit, in conjunction with the normal RAI indicators to determine when the condition has cleared. It may be useful to
enable the 200ms ESF RAI integration time with the RAIIE control bit (T1RCR2.1) in networks that utilize RAI-CI.
9.9.8.5 T1 Receive-Side Digital Milliwatt Code Generation
Receive-side digital milliwatt code generation involves using the T1 Receive Digital Milliwatt Registers
(T1RDMWE1–3) to determine which of the 24 T1 channels of the T1 line going to the backplane should be
overwritten with a digital milliwatt pattern. The digital milliwatt code is an 8-byte repeating pattern that represents a
1kHz sine wave (1E/0B/0B/1E/9E/8B/8B/9E). Each bit in the T1RDMWEx registers represents a particular channel.
If a bit is set to a one, then the receive data in that channel will be replaced with the digital milliwatt code. If a bit is
set to zero, no replacement occurs.
Rev: 101608
Receive Control Register 2
(T1RCR2.RRAIS)
Receive Control Register 2
(T1RCR2.RAIIE)
shows the registers related to the receive RAI (Yellow Alarm).
REGISTER
ADDRESSES
FRAMER 1
014h
014h
Select RAI to be T1 or J1.
Integration Enable for T1 ESF
DS26514 4-Port T1/E1/J1 Transceiver
FUNCTION
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