Specifications

ManualsBrandsMaxim ManualsNetwork CardDS33Z41

Maxim > App Notes > T/E Carrier and Packetized

Keywords: difference, T1, E1, channel, frame, superframe, extended, ESF, SF, D4, CRC-4, CAS, multiframe, CCS, RBS,

robbed bit, AIS, RAI, DMA

Dec 20, 2001

APPLICATION NOTE 590

Maxim® Telecommunications Frequently Asked Questions

Abstract: This FAQ discusses answers to general communication questions as well as Maxim device-specific questions.

This set of FAQs is designed to address some of the more common questions that may arise when using Maxim

telecommunication devices in new or existing designs. The questions are divided into different categories based on

specific information areas. Because some devices like the DS2155 have a combination of features, it is possible that

questions will span multiple categories.

Revision: June 25, 2009

Section 1. General Telecommunication Questions

In T1, what is the difference between superframe (SF)/D4 and extended superframe (ESF)?

What is the difference between T1 and E1?

What is the difference between T1 and J1?

What is SLC-96 and how does it relate to T1?

How are frames, channel time slots, and bits numbered in T1 and E1?

What are the differences between robbed-bit signaling (RBS), channel-associated signaling (CAS), and common-

channel signaling (CCS)?

What are the red, blue, and yellow alarms in a T1 system?

What are the alarm indication signal (AIS), remote alarm indication (RAI), and distant multiframe alarm (DMA) in

an E1 system?

What is the difference between AMI, B8ZS, and HDB3?

10.

What are the names of the regulatory bodies that govern the requirements for network interface line protection?

11.

What is the difference between jitter and wander?

12.

What standards bodies govern telecommunications equipment compliance?

13.

When the boundary scan is not used, what will be the pin conditions for the JTAG test access pins?

14.

For a universal T1/E1 interface on the customer side, do T1/E1 service providers expect customer equipment to

provide a connection between the Tx and Rx pairs through the transformer center taps? Or, can the T1/E1 service

provider ignore this connection and leave it out of the design?

15.

What is the difference between channelized and unchannelized T1?

16.

Can I modify the codes of Maxim telecommunication drivers?

Section 2. General Device Operation Questions

What are the standard register settings for a Maxim telecommunication device?

What software is available for use with Maxim telecommunication devices?

Can you provide an example design using various processors?

Can you provide a reference design for the network interface?

What is the meaning of the markings on Maxim devices?

What is the difference between the device identification register (IDR) value and the device revision markings on

Maxim devices?

What do the suffixes after Maxim telecommunication device names indicate?

What kind of operating system is needed for Maxim telecommunication drivers?

Page 1 of 22

Summary of content (22 pages)

PAGE 1
Maxim > App Notes > T/E Carrier and Packetized Keywords: difference, T1, E1, channel, frame, superframe, extended, ESF, SF, D4, CRC-4, CAS, multiframe, CCS, RBS, robbed bit, AIS, RAI, DMA Dec 20, 2001 APPLICATION NOTE 590 Maxim® Telecommunications Frequently Asked Questions Abstract: This FAQ discusses answers to general communication questions as well as Maxim device-specific questions.
PAGE 2
Section 3. Framer/Single-Chip Transceiver Questions 1. How are the DS21x5y, DS215y, or other telecommunication devices initialized? 2. Do Maxim telecommunication devices support unframed or transparent-mode operation? 3. Is it necessary to repeat the same data on the TSIG pin for an entire multiframe when using hardware-based signaling? 4. How are JTAG functions implemented on SCT multichip modules such as the DS21Q352/DS21Q55? 5. Is the DS2155 pin compatible with other Maxim SCTs? 6.
PAGE 3
Section 7. Design Kit Questions 1. 2. 3. 4. How can I get the most updated definition files for the T1E1DK? What software is available for Maxim telecommunication design kits? What telecommunication design kits are currently available from Maxim? When designing a board with a Maxim telecommunication device, is there any restriction on PCB trace length from the device to the transformer? Section 8. TDM-over-Packet (TDMoP) Questions 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
PAGE 4
Q4. What is SLC-96 and how does it relate to T1? A4. SLC-96 (pronounced "slick 96") is used in conjunction with T1 as a digital-loop carrier system, which provides service for up to 96 subscribers over three to five separate T1 lines. SLC-96 was the first widely deployed digital-loop carrier system. SLC-96 operation consists of two terminals: a central-office terminal (COT) and a remote terminal (RT).
PAGE 5
Q9. What is the difference between AMI, B8ZS, and HDB3? A9. AMI, B8ZS, and HDB3 are different types of line coding used in T1 and E1 communications systems. AMI (alternate mark inversion) is used in both T1 and T1 systems. B8ZS (bipolar with 8 zeros substitution) is used in T1 systems. HDB3 (high-density bipolar 3) is used in E1 systems. AMI is the most basic encoding scheme, in which ones are represented by voltage pulses and zeros are represented by the lack of a voltage pulse.
PAGE 6
● ● ● ● ● ● ● American National Standards Institute - ANSI (www.ansi.org) European Telecommunications Standards Institute - ETSI (www.etsi.org) International Telecommunication Union - ITU (www.itu.int) Telecommunication Technology Committee - TTC (www.ttc.or.jp) Telecommunications Industry Association - TIA (www.tiaonline.org) Telcordia Technologies, Inc. - Telcordia (www.telcordia.com) Underwriters Laboratories, Inc. - UL (www.ul.com), UL Europe (www.ul-europe.com) Q13.
PAGE 7
2. General Device Operation Questions Q1. What are the standard register settings for a Maxim telecommunication device? A1. Because there are many different ways that a T1, J1, E1, T3, or E3 device can communicate, there are no standard register settings. After initialization, there are three register types that control all major device operations. These are the receive control registers (RCRx), the transmit control registers (TCRx), and the common control registers (CCRx). Q2.
PAGE 8
For all Maxim T1/E1 devices with an 8-bit data bus, the device identification register (IDR) is eight bits in length. The upper four bits are used to identify the device family (e.g., the DS2155, DS21354, DS21552, etc.) The lower four bits are used to identify the specific revision of the die.
PAGE 9
single-port device contains a JTAG test access-port controller, and because the BSDL language lacks the ability to define multiple test access-port controllers. In the module, some pins such as address and data buses are tied together. The JTAG pins are either tied in parallel or daisy-chained, as appropriate. More detail can be found in the device's data sheets. To create the proper JTAG scan chain, four copies of the single-port version of the device need to be placed in the JTAG chain.
PAGE 10
Q7. What are some common problems and solutions when using the DS2155's internal HDLCs? A7. The DS2155 SCT has the ability to transmit and receive packet data over a T1/E1 or J1 line. This device contains two high-level, data-link controllers (HDLC), each of which can be configured for use with time slots, Sa bits (E1 mode), or the FDL (T1 mode). Each controller has a 128-byte FIFO in the transmit and receive paths.
PAGE 11
The DS21455 is a monolithic version of the DS21Q55, and is meant to be a drop-in replacement that is package, pin, and software compatible. The DS21458 contains exactly the same die as the DS21455 and is software compatible, but it is produced in a smaller, 17mm x 17mm package. Note: New designs should use the DS21455 instead of the DS21Q55. Q10. What is the functional behavior of the RCLK pin output when the signal at the network connection of RTIP/RRING is lost? A10.
PAGE 12
Q5. When the cable is unplugged for the network interface, why does the receive carrier loss (RCL) bit in the status register or the pin of the LIU or SCT occasionally report an incorrect status? A5. It is unlikely that the device actually reports the RCL status incorrectly. The most common cause of this problem is that a noise/signal source is coupling into the receive-side interface (the RTIP and RRING pins).
PAGE 13
Q9. Is it possible to use a sine-wave oscillator instead of a square-wave oscillator to supply different frequencies at the CLAD for the DS325x? A9. Yes. It is possible to use a sine-wave oscillator to supply sinusoidal frequencies to the input of the DS325x's CLAD. The lowest voltage of the sine wave cannot go below the diode drop, and it is recommended that the voltage is a 3.0V sine wave with minimum of 0V. Q10.
PAGE 14
Q4. Why do the DS21372/DS2172 receive synchronizers sometimes lock to patterns other than the transmitted pattern in repetitive-pattern mode? A4. When the DS21372 and DS2172 are used to generate repetitive patterns, the receiver only searches for a repeating pattern of the same length as the pattern being transmitted. It does not verify that the receive pattern exactly matches the transmit pattern. Once the device has received a pattern of equal length, synchronization is declared.
PAGE 15
Q3. How is the absolute address calculated in the DS31256 HDLC controller? A3. The absolute address, also known as the real address or machine address, is a fixed address in memory. The absolute address is the base address plus the actual address being used by the device. For proper operation, the absolute address must be allocated correctly when configuring the DMA controller in the device.
PAGE 16
Q4. When designing a board with a Maxim telecommunication device, is there any restriction on PCB trace length from the device to the transformer? A4. Application note 3410, "Guidelines for Laying Out T3 and E3 Network Interfaces," explains how to layout the network interfaces for Maxim T1/E1 and T3/E3 products. This application note provides layout considerations, trace-widths calculations, and different scenarios for ease of design.
PAGE 17
TXD[3:0] Transmit Data RXD[3:0] Receive Data TX_EN Transmit Enable RX_DV Receive Data Valid TX_ERR Transmit Error RX_ERR Receive Error COL Collision Detect CRS Carrier Sense CLK_TX Transmit Clock CLK_RX Receive Clock Figure 2 shows the connections between the DS34T108 and a generic Ethernet PHY in RMII mode. Here, the pin count has been reduced to 8 signals with the Tx data and Rx data being transmitted synchronously with respect to a REF_CLK. In this case, the REF_CLK is CLK_TX.
PAGE 18
transmitted between two TDMoIP edge devices. Sometimes, a bundle can be called a pseudowire. Q4. I am getting bit errors with the DS34T108 in E1 internal mode when I use all 8 ports. All other modes operate correctly. What is the cause of these errors, and is there a solution? A4. The A1 version of the DS34T108 does have issues when transmitting data on all 8 ports in E1 mode. The problem has to do with the internal TDM framer of the device—there is a bandwidth issue with the internal synchronizer.
PAGE 19
In Maxim TDMoP devices, for an ARP request, all the fields are filled in except the target hardware address. When a system receives an ARP request, it fills in its hardware address, swaps the two sender addresses with the two target addresses, sets the 'operation' field to 2, and sends the reply. Q7. What are the ground considerations when using an Ethernet PHY interface? A7. With any electrical system, choosing the appropriate grounding scheme is crucial for proper operation.
PAGE 20
Q9. What is the difference between TIE and MTIE? A9. TIE, short for time interval error, is defined as the phase difference between a measured clock edge and the ideal clock edge locations. These values are typically measured in nanoseconds. When plotted over a given amount of time, the TIE values can show how a given signal can shift in both phase and frequency to an ideal reference, as shown in Figures 4 and 5. Figure 4. TIE measurement against an ideal source. Figure 5. Typical TIE plotted over time.
PAGE 21
Figure 6. Typical MTIE graph with an MTIE mask. Q10. How can the user send OAM packets using the DS34T108? A10. OAM (operations, administration, and maintenance) is a general term used to describe the processes, activities, tools, standards, etc. involved with operation, administration, and maintenance of any system. PING and ARP are two examples of OAM packets. The main CPU is responsible for building the OAM packets and then passing them to the DS34T108.
PAGE 22
1. 2. 3. 4. First 4MB, 0x1000000 — 0x13FFFFF is for jitter buffer Next 1MB, 0x1400000 — 0x14FFFFF is for transmit buffer Next 0.