78M6612-IMR/F Maxim Integrated Products, 78M6612-IMR/F Datasheet - Page 61

• Manufacturer Part Number: 78M6612-IMR/F
• Description: IC POWER MEASUREMENT AC 68-QFN
• Manufacturer: Maxim Integrated Products

Specifications of 78M6612-IMR/F

• Mounting Style: SMD/SMT
• Package / Case: QFN-68
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS_6612_001
If there is no battery when system power returns, the part will switch to mission mode when PLL_OK
rises. All configuration bits will be in reset state, and RTC and MPU RAM data will be unknown and must
be initialized by the MPU.
2.5 Wake Up Behavior
As described above, the 78M6612 will always wake up in mission mode when system power is restored.
Additionally, the part will wake up in BROWNOUT mode when a timeout of the wake-up timer occurs.
2.5.1 Wake on Timer
If the part is in SLEEP or LCD mode, it can be awakened by the wake-up timer. Until this timer times
out, the MPU is in reset due to WAKE being low. When the wake-up timer times out, the WAKE signal
rises and within three crystal cycles, the MPU begins to execute. The MPU can determine whether the
timer woke it by checking the AUTOWAKE interrupt flag (IE_WAKE).
The wake-up timer begins timing when the part enters LCD or SLEEP mode. Its duration is controlled by
WAKE_PRD[2:0] and WAKE_RES. WAKE_RES selects a timer LSB of either 1 minute (WAKE_RES=1) or
2.5 seconds (WAKE_RES=0). WAKE_PRD[2:0] selects a duration of from 1 to 7 LSBs.
The timer is armed by WAKE_ARM=1. It must be armed at least three RTC cycles before SLEEP or
LCD_ONLY is initiated. Setting WAKE_ARM presets the timer with the values in WAKE_RES and
2.6 Data Flow
The data flow between CE and MPU is shown in
engine (CE) sequentially processes the samples from the voltage inputs on pins IA, VA, IB, and VB,
performing calculations to measure active power (Wh), reactive power (VARh), A
quadrant measurement. These measurements are then accessed by the MPU, processed further and
output using the peripheral devices available to the MPU.
Rev. 1.2
WAKE_PRD and readies the timer to start when the MPU writes to SLEEP or LCD_ONLY. The timer is
reset and disarmed whenever the MPU is awake. Thus, if it is desired to wake the MPU periodically
(every 5 seconds, for example) the timer must be rearmed every time the MPU is awakened.
Samples
Pulses
Processor
CE
I/O RAM (Configuration RAM)
Pre-
Figure 25: MPU/CE Data Flow
IRQ
Data
Figure
Processor
25. In a typical application, the 32-bit compute
MPU
Post-
Processed
Metering
Data
2
h, and V
78M6612 Data Sheet
2
h for four-
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