3.9.3.2 POH

There are nine bytes of path over- head. The first byte of the path overhead is the path trace byte, J1. Its location with respect to the SONET/SDH TOH/SOH is indi- cated by the associated STS/AU pointer. The following sections define the transmitted values of the POH bytes. Where the byte names differ between SONET and SDH, the SONET name is listed first.

3.9.3.2.1 Path Trace (J1)

The HDMP-3001 can be pro- grammed to transmit either a

16-byte or a 64-byte path trace message in the J1 byte. The mes- sages are stored in TX_J1[63:0]_[7:0]. In SDH mode, the J1 byte is transmitted repeti- tively as the 16-byte sequence in TX_J1[15]_[7:0] down to TX_J1[0]_[7:0]. Otherwise, the 64-byte sequence in TX_J1[63]_[7:0] down to TX_J1[0]_[7:0] is transmitted. (The 16-byte sequence is used in the SDH mode, and the 64-byte sequence in the SONET mode.)

3.9.3.2.2 Path BIP-8 (B3)

The Bit Interleaved Parity 8 (BIP-

8)is transmitted as even parity (normal) if register bit B3_INV = 0. Otherwise, odd parity (incor- rect) is generated. The BIP-8 is calculated over all bits of the pre- vious SPE/VC (including the POH) before scrambling and placed into the B3 byte of the current SPE/VC before scrambling. By definition of BIP-8, the first bit of B3 pro- vides parity over the first bit of all bytes of the previous SPE/VC, the second bit of B3 provides parity over the second bit of all bytes of the previous SPE/VC, etc.

3.9.3.2.3 Signal Label (C2)

The signal label byte indicates the composition, e.g. LAPS or GFP, of

the SPE/VC. The provisioned value, TX_C2[7:0], is inserted into the generated C2 bytes.

3.9.3.2.4 Path Status (G1)

The receive side monitors B3 bit errors in the received SPE/VC. The number of B3 errors detected in each frame (0 to 8) is trans- ferred from the receive side to the transmit side for insertion into the transmit path status byte, G1, as a Remote Error Indication. If regis- ter bit PREI_INH = 0, the bits are set to the binary value (0000 through 1000, indicating between 0 and 8) equal to the number of

B3 errors most recently detected by the Receive Side POH monitor- ing block. Otherwise, they are set to all zeros.

Path RDI. Bit 5 of G1 can be used as a Path/AU Remote Defect Indi- cation, RDI-P, or bits 5, 6, and 7 of G1 can be used as an enhanced RDI-P indicator. The values trans- mitted in bits 5, 6, and 7 of G1 are taken either from the TX_G1[2:0] registers (if PRDI_AUTO = 0), or the HDMP-3001 automatically generates an enhanced RDI signal (if PRDI_AUTO = 1 and PRDI_ENH = 1), or a one bit RDI signal (if PRDI_AUTO = 1 and PRDI_ENH = 0). The values trans- mitted in bits 5, 6, and 7 of G1 are shown in Table 11.

If PRDI_AUTO = 1, the values shown above are transmitted for a minimum of 20 frames. Once 20 frames have been transmitted with the same value, the value corresponding to the current state of the defect indication values listed in Table 1 will be transmit- ted. Bit 8 of G1 (the LSB) is unused, and it is set to zero.

3.9.3.2.5 Other POH Bytes

The remaining POH bytes are not supported by the HDMP-3001 and

are transmitted as all zeros. These include the path user channel (F2), the position indicator (H4), the path growth/user channel (Z3/ F3), the path growth/path APS channel (Z4/K3), and the tandem connection monitoring (Z5/N1) bytes.

3.9.3.2.6SONET/SDH Frame Generation

The SONET/SDH frame generator creates an STS-3c/STM-1 by gen- erating the Transport (Section) Overhead (TOH/SOH) bytes, fill- ing the payload with bytes from SPE/VC, and scrambling all bytes of the SONET/SDH signal except for the first row of TOH/SOH bytes.

3.9.3.2.7Frame Alignment

HDMP-3001 does not support frame alignment in the transmit direction.

3.9.3.2.8Payload Generation

The SONET or SDH payload is normally filled with bytes from the SPE/VC. The J1 byte of the SPE/VC is placed into column 10 of row 1.

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Agilent Technologies HDMP-3001 3.2 POH, Path Trace J1, Path BIP-8 B3, Signal Label C2, Path Status G1, Other POH Bytes
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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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