py-sfp-eeprom 0.1.3

Python library for creating and manipulating SFP EEPROM data

Python SFP EEPROM

A Python library to manage SFP module EEPROM data based on SFF-8472 specifications.

Features

• Create A0h EEPROM from scratch
• Load A0h EEPROM from binary bytes
• Get and set individual EEPROM fields
• Automatic checksum calculation and validation
• Export EEPROM as 256-byte binary data
• Human-readable field access and information display
• Support for all SFF-8472 standard fields

Installation

Install from PyPI:

pip install py-sfp-eeprom

Or for development, you can install in editable mode:

pip install -e .

Quick Start

Creating an EEPROM from Scratch

from sfp_eeprom import SFPA0h

# Create a new empty EEPROM
eeprom = SFPA0h()

# Set vendor information
eeprom.set('vendor_name', 'ACME FIBER')
eeprom.set('vendor_pn', 'SFP-10G-LR')
eeprom.set('vendor_sn', 'ABC123456789')
eeprom.set('vendor_oui', bytes.fromhex('001122'))

# Set transceiver type using named constants
eeprom.set('identifier', SFPA0h.IDENTIFIER_SFP)    # SFP/SFP+/SFP28
eeprom.set('connector', SFPA0h.CONNECTOR_LC)       # LC connector
eeprom.set('encoding', SFPA0h.ENCODING_64B66B)     # 64B/66B encoding

# Set specifications
eeprom.set('wavelength', 1310)  # 1310nm
eeprom.set('br_nominal', 103)   # 10.3 Gbps

# Update checksums
eeprom.update_checksums()

# Export to binary file
with open('eeprom.bin', 'wb') as f:
    f.write(eeprom.to_bytes())

Loading an Existing EEPROM

from sfp_eeprom import SFPA0h

# Read from binary file
with open('eeprom.bin', 'rb') as f:
    data = f.read()

# Create EEPROM object
eeprom = SFPA0h.from_bytes(data)

# Access fields
print(f"Vendor: {eeprom.get('vendor_name')}")
print(f"Part Number: {eeprom.get('vendor_pn')}")
print(f"Serial: {eeprom.get('vendor_sn')}")

# Get comprehensive info
info = eeprom.get_info()
print(info)

Modifying EEPROM Values

from sfp_eeprom import SFPA0h

# Load existing EEPROM
eeprom = SFPA0h.from_bytes(data)

# Change serial number
eeprom.set('vendor_sn', 'NEW-SN-12345')

# Change wavelength
eeprom.set('wavelength', 1550)  # 1550nm

# Checksums are automatically recalculated
# when you use the set() method

# Export modified EEPROM
modified_data = eeprom.to_bytes()

Named Constants

The library provides named constants for common field values, making code more readable:

Identifier Types

• IDENTIFIER_UNKNOWN - Unknown/unspecified (0x00)
• IDENTIFIER_GBIC - GBIC (0x01)
• IDENTIFIER_SOLDERED - Soldered to motherboard (0x02)
• IDENTIFIER_SFP - SFP/SFP+/SFP28 (0x03)
• IDENTIFIER_XFP - XFP (0x06)
• IDENTIFIER_QSFP - QSFP (0x0C)
• IDENTIFIER_QSFP_PLUS - QSFP+ or later (0x0D)
• IDENTIFIER_QSFP28 - QSFP28 or later (0x11)
• And more...

Connector Types

• CONNECTOR_UNKNOWN - Unknown/unspecified (0x00)
• CONNECTOR_SC - SC connector (0x01)
• CONNECTOR_LC - LC connector (0x07)
• CONNECTOR_MT_RJ - MT-RJ connector (0x08)
• CONNECTOR_MU - MU connector (0x09)
• CONNECTOR_RJ45 - RJ45 connector (0x22)
• CONNECTOR_MPO_1X12 - MPO 1x12 connector (0x0C)
• And more...

Encoding Types

• ENCODING_UNSPECIFIED - Unspecified (0x00)
• ENCODING_8B10B - 8B/10B (0x01)
• ENCODING_4B5B - 4B/5B (0x02)
• ENCODING_NRZ - NRZ (0x03)
• ENCODING_64B66B - 64B/66B (0x06)

Extended Identifier

• EXT_IDENTIFIER_GBIC - GBIC definition (0x00)
• EXT_IDENTIFIER_SFF - SFF-8472 compliant (0x04)

Example using constants:

eeprom.set('identifier', SFPA0h.IDENTIFIER_SFP)
eeprom.set('connector', SFPA0h.CONNECTOR_LC)
eeprom.set('encoding', SFPA0h.ENCODING_64B66B)

Supported Fields

The library supports all standard SFF-8472 A0h fields:

Identification Fields

• identifier - Transceiver type (0x03 = SFP)
• ext_identifier - Extended identifier
• connector - Connector type (0x07 = LC)

Vendor Information

• vendor_name - 16-character vendor name
• vendor_oui - IEEE company ID (3 bytes)
• vendor_pn - Part number (16 characters)
• vendor_rev - Revision (4 characters)
• vendor_sn - Serial number (16 characters)
• date_code - Manufacturing date (8 characters: YYMMDD + lot code)

Transceiver Specifications

• transceiver - Compliance codes (8 bytes)
• encoding - Encoding type
• br_nominal - Nominal bit rate (units of 100 Mbps)
• br_max - Upper bit rate margin
• br_min - Lower bit rate margin
• wavelength - Wavelength in nm (or copper attenuation)

Link Lengths

• length_smf_km - Single-mode fiber, km
• length_smf - Single-mode fiber, 100m units
• length_50um - 50µm OM2 fiber, 10m units
• length_62_5um - 62.5µm OM1 fiber, 10m units
• length_copper - Copper cable, 1m units
• length_om3 - 50µm OM3 fiber, 10m units

Options and Diagnostics

• options - Implemented options (2 bytes)
• diagnostic_monitoring - Diagnostic monitoring type
• enhanced_options - Enhanced options
• sff8472_compliance - SFF-8472 compliance level

Checksums

• cc_base - Checksum for base ID (bytes 0-62)
• cc_ext - Checksum for extended ID (bytes 64-94)

API Reference

SFPA0h Class

__init__(data=None)

Create a new EEPROM instance. If data is provided, it must be exactly 256 bytes.

get(field_name)

Get a field value in human-readable format (str, int, or bytes).

set(field_name, value)

Set a field value. Automatically updates checksums for affected regions.

to_bytes()

Export the complete EEPROM as 256 bytes.

from_bytes(data) (class method)

Create an EEPROM instance from 256 bytes of data.

update_checksums()

Manually recalculate and update both CC_BASE and CC_EXT checksums.

validate_checksums()

Validate both checksums. Returns dict with cc_base and cc_ext boolean values.

get_info()

Get a dictionary of all human-readable EEPROM information.

Examples

Creating an EEPROM (examples/example.py)

See examples/example.py for a complete demonstration of creating an EEPROM from scratch, setting all fields, validating checksums, and exporting to a binary file.

python examples/example.py

This will create an eeprom_a0h.bin file with a complete, valid SFP EEPROM image.

Reading an EEPROM (examples/read_eeprom.py)

Use the examples/read_eeprom.py CLI tool to read and display information from an existing EEPROM binary file:

# Display EEPROM information
python examples/read_eeprom.py eeprom_a0h.bin

# Display with hex dump
python examples/read_eeprom.py eeprom_a0h.bin --hex

# Get help
python examples/read_eeprom.py --help

The tool displays:

• Identification information (transceiver type, connector type)
• Vendor information (name, OUI, part number, serial number, date code)
• Transceiver specifications (encoding, bit rate, wavelength)
• Supported link lengths
• Options and diagnostic monitoring information
• Checksum validation status
• Optional hex dump of the entire EEPROM

Exit codes:

• 0 - Success (checksums valid)
• 1 - File error or invalid EEPROM
• 2 - EEPROM loaded but checksums invalid

Specifications

Based on SFF-8472 (SFP MSA) specification for the A0h lower page (256 bytes).

License

This is free and unencumbered software released into the public domain.