UM1524

EEPROM log data structure

Doc ID 022901 Rev 1

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6.8

Size overview

Note:

EEPROM data structuring is done in a modular way to support future updates. Reconfigure

parameters in header file “emeter_datamgmt.h” to modify log structure entry count.

6.9

Entry structure

●

Calibration data log

CHV, CHP, CHS are calibration parameters for current and voltage channel for metering IC.

For more details on calibration parameters, refer to the metering IC datasheet on

www.st.com.

●

Total cumulative energy log

Two duplicate entries are stored. One at the start of EEPROM and another at the end of

EEPROM.

This is done to make sure that, if EEPROM is corrupted at one point, another entry with

correct CRC is considered as the valid value.

Table 5.

EEPROM parameter size overview

Parameter

Size (in bytes)

Calibration data

10 (3 bytes (CHV, CHP, CHS +7 dummy bytes for

future use))

Total cumulative energy duplicate entry 1

7(4 bytes + 2byte + 1 byte (CRC))

Cumulative energy till last month

42(7*6): without CRC

Maximum demand log

63(7*(3+3+3))

Monthly cumulative energy

42(7*6)

Average PF log

42(7*4+7*2)

Earth tamper log

175 (7*((4*(3+3)) +1))

Reverse log

175 (7*((4*(3+3)) +1))

Neutral missing log

175 (7*((4*(3+3)) +1))

Case tamper log

175 (7*((4*(3+3)) +1))

Total cumulative energy duplicate entry 2

7(4 bytes + 2byte+ 1 byte (CRC))

Count for CE overflow

1 byte

Power-down entry

6 byte

Table 6.

Calibration data Log

Calibration data

Start address

Size

(CHV, CHP, CHS, 7 times 0x00)

0x00

10