![](http://datasheet.mmic.net.cn/310000/ADE7754_datasheet_16240613/ADE7754_41.png)
REV. PrG 01/03
PRELIMINARY TECHNICAL DATA
ADE7754
–
41
–
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
Location
Bit
Mnemonic
Default
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.
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.
These bits are used to select the formula used for Active Energy calculation
WATM1
WAVM0
Active Energy calculation
0
0
VAxIA
+
0
1
VAx(IA-IB)
+
1
0
VAx(IA-IB)
+
1
1
Reserved
3-5
WATSEL
7
6-7
WATM
0
VBxIB
0
0
+
+
+
VCxIC
VCx(IC-IB)
VCxIC
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
Location
Bit
Mnemonic
Default
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.
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
(VA
rms
xIA
rms
). Setting bit 4 to logic one selects the second term of the formula
(VB
rms
xIB
rms
or (VA
rms
+VC
rms
)/2xIB
rms
or VA
rms
xIB
rms
depending on VAMOD configu-
ration). Setting bit 3 to logic one selects the first term of the formula (VC
rms
xIC
rms
). Any
combination of these bits are possible to address calibration and operational needs.
These bits are used to select the formula used for Active Energy calculation
VAMOD1
VAMOD0
Apparent Energy calculation
0
0
VA
rms
xIA
rms
+VB
rms
xIB
rms
+VC
rms
xIC
rms
0
1
VA
rms
xIA
rms
+(VA
rms
+VC
rms
)/2xIB
rms
+VC
rms
xIC
rms
1
0
VA
rms
xIA
rms
+VA
rms
xIB
rms
+VC
rms
xIC
rm
1
1
Reserved
3-5
VASEL
7
6-7
VAMOD
0