71M6541D Datasheet, PDF (2/166 Pages) Maxim Integrated Products – 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs

71M6541D/F/G and 71M6542F/G Data Sheet
Table of Contents
1 Introduction ................................................................................................................................. 10
2 Hardware Description.................................................................................................................. 11
2.1 Hardware Overview............................................................................................................... 11
2.2 Analog Front End (AFE) ........................................................................................................ 12
2.2.1 Signal Input Pins ....................................................................................................... 14
2.2.2 Input Multiplexer........................................................................................................ 15
2.2.3 Delay Compensation ................................................................................................. 19
2.2.4 ADC Pre-Amplifier ..................................................................................................... 20
2.2.5 A/D Converter (ADC)................................................................................................. 20
2.2.6 FIR Filter ................................................................................................................... 20
2.2.7 Voltage References................................................................................................... 20
2.2.8 71M6x01 Isolated Sensor Interface (Remote Sensor Interface).................................. 22
2.3 Digital Computation Engine (CE)........................................................................................... 24
2.3.1 CE Program Memory................................................................................................. 24
2.3.2 CE Data Memory....................................................................................................... 24
2.3.3 CE Communication with the MPU.............................................................................. 25
2.3.4 Meter Equations ........................................................................................................ 25
2.3.5 Real-Time Monitor (RTM) .......................................................................................... 25
2.3.6 Pulse Generators ...................................................................................................... 27
2.3.7 CE Functional Overview ............................................................................................ 28
2.4 80515 MPU Core .................................................................................................................. 31
2.4.1 Memory Organization and Addressing ....................................................................... 31
2.4.2 Special Function Registers (SFRs) ............................................................................ 33
2.4.3 Generic 80515 Special Function Registers ................................................................ 34
2.4.4 Instruction Set ........................................................................................................... 36
2.4.5 UARTs ...................................................................................................................... 36
2.4.6 Timers and Counters ................................................................................................. 39
2.4.7 WD Timer (Software Watchdog Timer) ...................................................................... 40
2.4.8 Interrupts................................................................................................................... 40
2.5 On-Chip Resources............................................................................................................... 48
2.5.1 Physical Memory ....................................................................................................... 48
2.5.2 Oscillator................................................................................................................... 50
2.5.3 PLL and Internal Clocks............................................................................................. 50
2.5.4 Real-Time Clock (RTC) ............................................................................................. 51
2.5.5 71M654x Temperature Sensor .................................................................................. 56
2.5.6 71M654x Battery Monitor........................................................................................... 57
2.5.7 UART and Optical Interface....................................................................................... 58
2.5.8 Digital I/O and LCD Segment Drivers......................................................................... 59
2.5.9 EEPROM Interface.................................................................................................... 70
2.5.10 SPI Slave Port........................................................................................................... 73
2.5.11 Hardware Watchdog Timer........................................................................................ 78
2.5.12 Test Ports (TMUXOUT and TMUX2OUT Pins)........................................................... 78
3 Functional Description ................................................................................................................ 80
3.1 Theory of Operation .............................................................................................................. 80
3.2 Battery Modes....................................................................................................................... 81
3.2.1 BRN Mode ................................................................................................................ 83
3.2.2 LCD Mode................................................................................................................. 83
3.2.3 SLP Mode ................................................................................................................. 84