Introduction
1 Definitions, Acronyms and Abbreviations
2 Overall Description
3 Metrology Interface Definition
- 3.1 Metrology Control Registers
  - 3.1.1 Metrology State Control
    Metrology State Control
  - 3.1.2 Metrology Feature Control Register
    Metrology Feature Control Register
  - 3.1.3 Harmonic Control Register
    Harmonic Control Register
  - 3.1.4 Meter Type Settings Register
    Meter Type Settings Register
  - 3.1.5 Number of Line Cycles for Integration Period
    Number of Line Cycles for Integration Period
  - 3.1.6 Max Number of Samples in an Integration Period
    Max Number of Samples in an Integration Period
  - 3.1.7 Pulse Control Register x (x = 0, 1, 2)
    Pulse Control Register x (x = 0, 1, 2)
  - 3.1.8 Meter Active Power Pulse Constant
    Meter Active Power Pulse Constant
  - 3.1.9 Meter Reactive Power Pulse Constant
    Meter Reactive Power Pulse Constant
  - 3.1.10 Meter Current Pulse Constant
    Meter Current Pulse Constant
  - 3.1.11 Meter Apparent Power Pulse Constant
    Meter Apparent Power Pulse Constant
  - 3.1.12 Creep Threshold for Active Energy
    Creep Threshold for Active Energy
  - 3.1.13 Creep Threshold for Quadergy
    Creep Threshold for Quadergy
  - 3.1.14 Creep Threshold of Phase Current
    Creep Threshold of Phase Current
  - 3.1.15 Creep Threshold for Apparent Energy
    Creep Threshold for Apparent Energy
  - 3.1.16 Power Offset Control Register
    Power Offset Control Register
  - 3.1.17 Active Power Offset Register
    Active Power Offset Register
  - 3.1.18 Reactive Power Offset Register
    Reactive Power Offset Register
  - 3.1.19 Apparent Power Offset Register
    Apparent Power Offset Register
  - 3.1.20 Voltage Swell Threshold
    Voltage Swell Threshold
  - 3.1.21 Voltage Sag Threshold
    Voltage Sag Threshold
  - 3.1.22 Current Conversion Factor
    Current Conversion Factor
  - 3.1.23 Voltage Conversion Factor
    Voltage Conversion Factor
  - 3.1.24 Current Channel Magnitude Calibration Constants
    Current Channel Magnitude Calibration Constants
  - 3.1.25 Voltage Channel Magnitude Calibration Constants
    Voltage Channel Magnitude Calibration Constants
  - 3.1.26 Per-Channel Phase Calibration Constants
    Per-Channel Phase Calibration Constants
  - 3.1.27 Waveform Capture Control Register
    Waveform Capture Control Register
  - 3.1.28 Capture Buffer Size
    Capture Buffer Size
  - 3.1.29 Waveform Capture Destination Buffer Address
    Waveform Capture Destination Buffer Address
  - 3.1.30 ATSENSE ADC Control Register 0
    ATSENSE ADC Control Register 0
  - 3.1.31 ATSENSE ADC Control Register 1
    ATSENSE ADC Control Register 1
  - 3.1.32 ATSENSE ADC Control Register 2
    ATSENSE ADC Control Register 2
  - 3.1.33 Per-Phase Active Power Offset Register
    Per-Phase Active Power Offset Register
  - 3.1.34 Per-Phase Reactive Power Offset Register
    Per-Phase Reactive Power Offset Register
- 3.2 Metrology Status Registers
- 3.3 Accumulated Output Quantities
- 3.4 Harmonic Analysis Output Quantities
- 3.5 Derived Output Quantities
4 Interface between Metrology and Application
5 Annex. Meter Forms
The service type determines what meter form is being implemented and how the Metrology DSP core interprets and processes the ADC values.
6 References
7 Revision History
Microchip Information

3.1.5 Number of Line Cycles for Integration Period

The measurement time unit, t_M, or integration period, is delineated by M-number of negative-to-positive zero-crossings of the fundamental frequency using a selected voltage signal. All primary output quantities are computed for this many number of cycles of the fundamental frequency.

M is the number of cycles of the integration period are provided as input into the metrology module.

Note: After changing this register, verify the value of the N_MAX register.

Note: If the phase voltage for frequency determination is not present, defined as >= 1/32 of max range, then the metrology module transitions to a default integration period of "N_MAX" samples. If phase voltage loss occurs before the expected number, then that specific integration period may end with some intermediate number of samples. In all cases, the number of samples used in an integration period is available in the output Register N, at the end of an integration period.

Presently, fixed-precision accumulation is scaled for a maximum integration period of 30 seconds (given max V & I inputs). This has to be changed if a one-minute integration period is desired.

Name:	M
Property:	Read-Write


Bit	31	30	29	28	27	26	25	24

Access
Reset


Bit	23	22	21	20	19	18	17	16

Access
Reset


Bit	15	14	13	12	11	10	9	8
					M[11:8]
Access					R/W	R/W	R/W	R/W
Reset					0	0	0	0


Bit	7	6	5	4	3	2	1	0
	M[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bits 11:0 – M[11:0] (uQ12.0)

Value	Description
0	Number of cycles for the measurement period will be determined automatically as the number of cycles closest to 1.0 second of integration time. The number of cycles is variable and the measurement period, t_M, will closely track 1.0 sec of measurement time, regardless of line frequency.
Other	Number of cycles is fixed and the measurement period, t_M, will vary with line frequency.