•If PTR_STATE[1:0] = 00 and {LOP2,AIS2} = 11 and {LOP3,AIS3} = 11, which is the normal case, then RX_PAIS = 0 and RX_LOP = 0.

•If PTR_STATE[1:0] = 01 and {LOP2,AIS2} = 01 and {LOP3,AIS3} = 01, then RX_PAIS = 1 and RX_LOP = 0.

•If PTR_STATE[1:0] = 10 and {LOP2,AIS2} = 01 and {LOP3,AIS3} = 10, then RX_PAIS = 0 and RX_LOP = 1.

The RX_PAIS and RX_LOP signals contribute to the Path Remote De- fect Indication (PRDI). Changes in these state values are indicated by the RX_PAIS_D and RX_LOP_D delta bits.

3.9.4.7 Pointer Interpretation

The first H1-H2 byte pair is inter- preted to locate the start of the SPE/VC. The rules for pointer interpretation are:

1.During normal operation, the pointer locates the start of the SPE/VC.

2.Any variation from the current accepted pointer is ignored unless a consistent new value is received three times consecutively, or it is preceded by one of the rules 3, 4, or 5. Any consistent new value received three times consecutively overrides rules 3 or 4.

3.In the case of SONET mode, if at least three out of four of the NDF bits match the disabled indication (0110) and at least 8 out of 10 of the pointer value bits match the current accepted pointer with its I-bits inverted, a positive justification is indicated. The byte following the H3 byte is considered a positive stuff byte, and the

current accepted pointer value is incremented by 1 (mod 783).

In the case of SDH mode, if at least three out of four of the NDF bits match the disabled indication (0110), three or more of the pointer value I-bits and two or fewer of the pointer value D-bits match the current accepted pointer with all its bits inverted, and either the received SS-bits are 10 or RX_SS_EN = 0, a positive justification is indicated. The byte following the H3 byte is considered a positive stuff byte, and the current accepted pointer value is incremented by 1 (mod 783).

4.In the case of SONET mode, if at least three out of four of the NDF bits match the disabled indication (0110) and at least eight out of ten of the pointer value bits match the current accepted pointer with its D-bits inverted, a negative justification is indicated. The H3 byte is considered a negative stuff byte (it is part of the SPE), and the current accepted pointer value is decremented by 1 (mod 783).

In the case of SDH mode, if at least three out of four of the NDF bits match the disabled indication (0110), three or more of the pointer value D- bits and two or fewer of the pointer value I-bits match the current accepted pointer with all its bits inverted, and either the received SS-bits are 10 or RX_SS_EN = 0, a negative justification is indicated. The H3 byte is considered a negative stuff byte (it is part of the VC), and the current accepted pointer value is decremented by 1 (mod 783).

5.In the case of SONET mode, if at least three out of four of the NDF bits match the enabled indication (1001), and the pointer value is between 0 and 782, the received pointer replaces the current accepted pointer value. For SDH mode, if at least three out of four of the NDF bits match the enabled indication (1001), the pointer value is between 0 and 782, and either the received SS-bits are 10 or RX_SS_EN = 0, the received pointer replaces the current accepted pointer value. Using these pointer interpretation rules, the Pointer Interpreter block determines the location of SPE/VC payload and POH bytes.

3.9.4.8 Pointer Processing

The pointer tracking algorithm implemented in the HDMP-3001 device is illustrated in Figure 16. Please refer to G.783 and GR-253 for definitions of the transitions. The pointer tracking state ma- chine is based on the pointer tracking state machine found in the ITU-T requirements, and is also valid for both Bellcore and ANSI. The AIS to LOP transition of the state machine does not oc- cur in Bellcore mode (i.e., the BELLCORE bit is set to logic one).

For STM-1/STS-3c operation, the pointer is a binary number with the range of 0 to 782 (decimal). It is a 10-bit value derived from the two least significant bits of the H1 byte, with the H2 byte concat- enated, to form an offset in 3-byte counts from the H3 byte location. For example, for an STM-1 signal, a pointer value of zero indicates that the VC-4 starts in the byte lo- cation three bytes after the H3 byte, whereas an offset of 87 indi-

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Agilent Technologies HDMP-3001 manual Pointer Interpretation, Current accepted pointer value is incremented by 1 mod
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HDMP-3001 specifications

Agilent Technologies, a prominent name in electronics and measurement technology, offers a wide range of products that cater to various industries. Among its notable offerings is the HDMP-3001, a high-speed, serial data transceiver designed to facilitate robust communications in electronic systems. The HDMP-3001 stands out with its ability to handle high bandwidths, making it particularly suited for applications requiring rapid data transfer, such as telecommunications, computer networking, and high-performance computing.

One of the main features of the HDMP-3001 is its advanced signaling technology. By employing differential signaling, the transceiver minimizes electromagnetic interference and enhances signal integrity. This is crucial in environments with multiple electronic devices operating simultaneously, as it ensures data is transmitted clearly and without degradation.

The HDMP-3001 operates at a maximum data rate of 1 Gbps, allowing for efficient data transfer over short distances. This capability is coupled with a flexible architecture that enables users to configure the transceiver for various applications. The device supports both point-to-point and point-to-multipoint configurations, giving engineers the versatility they need in designing communication links.

Moreover, the HDMP-3001 features on-chip clock recovery functionality, which simplifies system design by reducing the number of external components needed. This built-in feature allows the transceiver to maintain synchronization even as data rates increase, further enhancing performance.

The low power consumption characteristic of the HDMP-3001 is another notable advantage. This makes it an attractive choice for battery-operated devices and systems where power efficiency is critical. The transceiver’s design ensures optimal performance while minimizing heat generation and power draw, enabling longer operational lifetimes.

In terms of physical characteristics, the HDMP-3001 comes in a compact, surface-mount package, allowing for easier integration into various circuit board designs. The small form factor, combined with its innovative technology, makes it a popular choice among engineers seeking to improve data transmission reliability without compromising on space or power constraints.

Overall, Agilent Technologies' HDMP-3001 is a formidable solution for high-speed serial data transmission, characterized by its robust performance, low power consumption, and versatile configuration options. With these features, it continues to be an essential component in the evolving landscape of electronic communications.
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