REV. PrG 01/03

PRELIMINARY TECHNICAL DATA

ADE7754

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Watt Mode Register (0Dh)

The phases involved in the Active Energy measurement of the ADE7754 are defined by writing to the WATMODE register.

Table XIV below summarizes the functionality of each bit in the WATMODE register .

Table XIV WATMODE Register

Bit

Bit

Default

Location

Mnemonic

Value

Description

0-2

LWATSEL

7

These bits are used to select separately each part of the formula, depending on the Line

Active Energy measurement method. The behavior of these bits is the same as WATSEL

bits. Bit 2 selects the first term of the formula and so on.

3-5

WATSEL

7

These bits are used to select separately each part of the formula, depending on the Active

Energy measurement method. These bits are also used to enable the Negative power

detection available in bits 12-14 of CFNUM register - see Table XI. Setting bit 5 to logic

one selects the first term of the formula (VAxIA or VAx(IA-IB)). Setting bit 4 to logic one

selects the second term of the formula (VBxIB or 0 depending on WATMOD configu-

ration). Setting bit 3 to logic one selects the last term of the formula (VCxIC or

VCx(IC-IB)). Any combination of these bits are possible to address calibration and

operational needs.

6-7

WATM

0

These bits are used to select the formula used for Active Energy calculation

WATM1

WAVM0

Active Energy calculation

0

0

VAxIA

+

VBxIB

+

VCxIC

0

1

VAx(IA-IB) +

0

+

VCx(IC-IB)

1

0

VAx(IA-IB) +

0

+

VCxIC

1

1

Reserved

VA Mode Register (0Eh)

The phases involved in the Apparent Energy measurement of the ADE7754 are defined by writing to the VAMODE register.

Table XV below summarizes the functionality of each bit in the VAMODE register .

Table XV VAMode Register

Bit

Bit

Default

Location

Mnemonic

Value

Description

0-2

LVASEL

7

These bits are used to select separately each part of the formula, depending on the Line

Apparent Energy measurement method. The behavior of these bits is the same as VASEL

bits. Bit 2 selects the first term of the formula and so on.

3-5

VASEL

7

These bits are used to select separately each part of the formula, depending on the Apparent

Energy measurement method. Setting bit 5 to logic one selects the first term of the formula

combination of these bits are possible to address calibration and operational needs.

6-7

VAMOD

0

These bits are used to select the formula used for Active Energy calculation

VAMOD1

VAMOD0

Apparent Energy calculation

00

01

10

1

1

Reserved