ADE5166_08 AD [Analog Devices], ADE5166_08 Datasheet - Page 35

• Manufacturer Part Number: ADE5166_08
• Description: Single-Phase Energy Measurement IC with 8052 MCU, RTC, and LCD Driver
• Manufacturer: AD [Analog Devices]

ENERGY MEASUREMENT
The ADE5166/ADE5169 offer a fixed function, energy measure-
ment, digital processing core that provides all the information
needed to measure energy in single-phase energy meters. The
part provides two ways to access the energy measurements:
direct access through SFRs for time sensitive information and
indirect access through address and data SFRs for the majority
of energy measurements. The I
registers are readily available through the SFRs, as shown in
Table 30. Other energy measurement information is mapped
to a page of memory that is accessed indirectly through the
MADDPT, MDATL, MDATM, and MDATH SFRs. The address
and data SFRs act as pointers to the energy measurement
internal registers.
ACCESS TO ENERGY MEASUREMENT SFRs
Access to the energy measurement SFRs is achieved by reading
or writing to the SFR addresses detailed in Table 30. The internal
data for the MIRQx SFRs is latched byte by byte into the SFR
when the SFR is read.
The WAV1x, WAV2x, VRMSx, and IRMSx registers are all 3-byte
SFRs. The 24-bit data is latched into these SFRs when the high
byte is read. Reading the low or medium byte before the high
byte results in reading the data from the previous latched sample.
Sample code to read the VRMSx register is as follows:
MOV
MOV
MOV
ACCESS TO INTERNAL ENERGY MEASUREMENT
REGISTERS
Access to the internal energy measurement registers is achieved
by writing to the energy measurement pointer address SFR
(MADDPT, Address 0x91). This SFR selects the energy measure-
ment register to be accessed and determines if a read or a write
is performed (see Table 29).
Table 29. Energy Measurement Pointer Address SFR
(MADDPT, Address 0x91)
Bit
7
[6:0]
Writing to the Internal Energy Measurement Registers
When Bit 7 of the energy measurement pointer address SFR
(MADDPT, Address 0x91) is set, the content of the MDATx
SFRs (MDATL, MDATM, and MDATH) is transferred to the
R1, VRMSH
R2, VRMSM
R3, VRMSL
Description
1 = write, 0 = read
Energy measurement internal register address
//latches data in VRMSH,
VRMSM, and VRMSL SFRs
rms
, V
rms
, interrupts, and waveform
Rev. 0 | Page 35 of 148
internal energy measurement register designated by the address
in the MADDPT SFR. If the internal register is one byte long,
only the MDATL SFR content is copied to the internal register,
while the MDATM SFR and MDATH SFR contents are ignored.
The energy measurement core functions with an internal clock of
4.096 MHz∕5 or 819.2 kHz. Because the 8052 core functions with
another clock, 4.096MHz∕2
clock environments when CD = 0 or 1 is an issue. When data is
written to the internal energy measurement registers, a small
wait period needs to be implemented before another read or
write to these registers can take place.
Sample code to write 0x0155 to the 2-byte SAGLVL register
located at 0x14 in the energy measurement memory space is as
follows:
MOV
MOV
MOV
MOV
DJNZ
Reading the Internal Energy Measurement Registers
When Bit 7 of energy measurement pointer address SFR
(MADDPT, Address 0x91) is cleared, the content of the internal
energy measurement register designated by the address in
MADDPT is transferred to the MDATx SFRs. If the internal
register is one byte long, only the MDATL SFR content is updated
with a new value, and the MDATM SFR and MDATH SFR
contents are reset to 0x00.
The energy measurement core functions with an internal clock
of 4.096 MHz∕5 or 819.2 kHz. Because the 8052 core functions
with another clock, 4.096MHz∕2
two clock environments when CD = 0 or 1 is an issue. When data
is read from the internal energy measurement registers, a small
wait period needs to be implemented before the MDATx SFRs
are transferred to another SFR.
Sample code to read the peak voltage in the 2-byte VPKLVL
register located at 0x16 into the data pointer is as follows:
MOV
MOV
DJNZ
MOV
MOV
MDATM,#01h
MDATL,#55h
MADDPT,#SAGLVL_W (Address 0x94)
A,#05h
ACC,$
;Next write or read to energy
measurement SFR can be done after
this.
MADDPT,#VPKLVL_R (Address 0x16)
A,#05h
ACC,$
DPH,MDATM
DPL,MDATL
CD
, synchronization between the two
CD
, synchronization between the
ADE5166/ADE5169