Datasheet
Table Of Contents
- 1 Hardware Description
- 1.1 Hardware Overview
- 1.2 Analog Front End (AFE)
- 1.3 Digital Computation Engine (CE)
- 1.4 80515 MPU Core
- 1.4.1 Memory Organization and Addressing
- 1.4.2 Special Function Registers (SFRs)
- 1.4.3 Generic 80515 Special Function Registers
- 1.4.4 Special Function Registers (SFRs) Specific to the 71M6531D/F and 71M6532D/F
- 1.4.5 Instruction Set
- 1.4.6 UARTs
- 1.4.7 Timers and Counters
- 1.4.8 WD Timer (Software Watchdog Timer)
- 1.4.9 Interrupts
- 1.5 On-Chip Resources
- 1.5.1 Oscillator
- 1.5.2 Internal Clocks
- 1.5.3 Real-Time Clock (RTC)
- 1.5.4 Temperature Sensor
- 1.5.5 Physical Memory
- 1.5.6 Optical Interface
- 1.5.7 Digital I/O – 71M6531D/F
- 1.5.8 Digital I/O – 71M6532D/F
- 1.5.9 Digital IO – Common Characteristics for 71M6531D/F and 71M6532D/F
- 1.5.10 LCD Drivers – 71M6531D/F
- 1.5.11 LCD Drivers – 71M6532D/F
- 1.5.12 LCD Drivers – Common Characteristics for 71M6531D/F and 71M6532D/F
- 1.5.13 Battery Monitor
- 1.5.14 EEPROM Interface
- 1.5.15 SPI Slave Port
- 1.5.16 Hardware Watchdog Timer
- 1.5.17 Test Ports (TMUXOUT pin)
- 2 Functional Description
- 3 Application Information
- 3.1 Connection of Sensors
- 3.2 Connecting 5-V Devices
- 3.3 Temperature Measurement
- 3.4 Temperature Compensation
- 3.5 Connecting LCDs
- 3.6 Connecting I2C EEPROMs
- 3.7 Connecting Three-Wire EEPROMs
- 3.8 UART0 (TX/RX)
- 3.9 Optical Interface (UART1)
- 3.10 Connecting the V1 Pin
- 3.11 Connecting the Reset Pin
- 3.12 Connecting the Emulator Port Pins
- 3.13 Connecting a Battery
- 3.14 Flash Programming
- 3.15 MPU Firmware
- 3.16 Crystal Oscillator
- 3.17 Meter Calibration
- 4 Firmware Interface
- 4.1 I/O RAM and SFR Map – Functional Order
- 4.2 I/O RAM Description – Alphabetical Order
- 4.3 CE Interface Description
- 5 Electrical Specifications
- 5.1 Absolute Maximum Ratings
- 5.2 Recommended External Components
- 5.3 Recommended Operating Conditions
- 5.4 Performance Specifications
- 5.4.1 Input Logic Levels
- 5.4.2 Output Logic Levels
- 5.4.3 Power-Fault Comparator
- 5.4.4 Battery Monitor
- 5.4.5 Supply Current
- 5.4.6 V3P3D Switch
- 5.4.7 2.5 V Voltage Regulator
- 5.4.8 Low-Power Voltage Regulator
- 5.4.9 Crystal Oscillator
- 5.4.10 LCD DAC
- 5.4.11 LCD Drivers
- 5.4.12 Optical Interface
- 5.4.13 Temperature Sensor
- 5.4.14 VREF
- 5.4.15 ADC Converter, V3P3A Referenced
- 5.5 Timing Specifications
- 5.6 Typical Performance Data
- 5.7 71M6531D/F Package
- 5.8 71M6532D/F Package
- 5.9 Pin Descriptions
- 6 Ordering Information
- 7 Related Information
- 8 Contact Information
- Appendix A: Acronyms
- Appendix B: Revision History
![](/manual/maxim-integrated/71m6531f-im-f/datasheet-english/images/img-93.png)
FDS 6531/6532 005 Data Sheet 71M6531D/F-71M6532D/F
Rev 2 93
0x90
I1SQSUM_X
LSB
I
= 6.6952*10
-13
IMAX
2
/ In_8
2
A
2
h
0x93
V0SQSUM_X
The sum of squared voltage samples from each element.
LSB
V
= 6.6952*10
-13
VMAX
2
V
2
h
0x94
V1SQSUM_X
0x45
WSUM_ACCUM
These registers contain roll-over accumulators for WPULSE and
VPULSE respectively.
0x46
VSUM_ACCUM
0x47
SUM3_ACCUM
These registers contain roll-over accumulators for pulse outputs
XPULSE and YPULSE respectively.
0x48
SUM4_ACCUM
0x99
I0SQRES_X
These registers hold residual current measurements with double-
precision accuracy. The exact current ISQn is:
ISQn = InSQSUM_X + 2
32
* InSQRES_X
0x9A
I1SQRES_X
The RMS values can be computed by the MPU from the squared current and voltage samples as follows:
ACC
SI
RMS
N
FLSBIxSQSUM
Ix
⋅⋅⋅
=
3600
Other Measurement Parameters
Table 63 describes the CE measurement parameters listed below:
• MAINEDGE_X: Useful for implementing a real-time clock based on the input AC signal. MAINEDGE_X
is the number of half-cycles accounted for in the last accumulated interval for the AC signal.
• TEMP_RAW: May be used by the MPU to monitor the chip temperature or to implement temperature
compensation.
• GAIN_ADJ: A scaling factor for measurements based on the temperature. GAIN_ADJ can be controlled
by the MPU for temperature compensation.
• VBAT_SUM_X: This result can be used to calculate the measured battery voltage (VBAT).
Table 63: Useful CE Measurement Parameters
CE
Address
Name Default Description
0x83
MAINEDGE_X
N/A
The number of zero crossings of the voltage selected with
FREQSELn in the previous accumulation interval. Zero crossings
are either direction and are debounced.
0x81
TEMP_RAW_X
N/A
The filtered, un-scaled reading from the temperature sensor.
0x9D
TEMP_X
N/A
This register contains the difference between the die temperature
and the reference/calibration temperature as established in the
TEMP_NOM register, measured in 0.1°C.
0x40
GAIN_ADJ
16384
Scales all voltage and current inputs. A value of 16384 provides
unity gain. This register is used by the CE or by the MPU to
implement temperature compensation.
0x84
VBAT_SUM_X
N/A
Output of the battery measurement. This value is equivalent to
twice the measured ADC value.
4.3.8 Pulse Generation
Table 64 describes the CE pulse generation parameters WRATE, APULSEW, APULSER, APULSE2 and
APULSE3.
WRATE controls the number of pulses that are generated per measured Wh and VARh quantities. The lower
WRATE is the slower the pulse rate for measured energy quantity. The metering constant Kh is derived from
WRATE as the amount of energy measured for each pulse. That is, if Kh = 1 Wh/pulse, a power applied
to the meter of 120 V and 30 A (3,600 W) results in one pulse per second. If the load is 240 V at 150 A
(36,000 W), ten pulses per second will be generated.
The maximum pulse rate is 7.5 kHz for APULSEW and APULSER and 1.2 kHz for APULSE2 and APULSE3.
ACC
SV
RMS
N
FLSBVxSQSUM
Vx
⋅⋅⋅
=
3600