71M6542F MAXIM [Maxim Integrated Products], 71M6542F Datasheet - Page 84

• Manufacturer Part Number: 71M6542F
• Description: 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs
• Manufacturer: MAXIM [Maxim Integrated Products]

71M6541D/F/G and 71M6542F/G Data Sheet
3.2.3 SLP Mode
When the V3P3SYS pin voltage drops below 2.8 VDC, the 71M654x enters BRN mode and the V3P3D
pin obtains power from the VBAT pin instead of the V3P3SYS pin. Once in BRN mode, the MPU may
invoke SLP mode by setting the SLEEP bit (I/O RAM 0x28B2[7]). The purpose of SLP mode is to
consume the least amount power while still maintaining the RTC (Real Time Clock), temperature
compensation of the RTC, and the non-volatile portions of the I/O RAM.
In SLP mode, the V3P3D pin is disconnected, removing all sources of current leakage from the VBAT pin.
The non-volatile I/O RAM locations and the SLP mode functions, such as the temperature sensor,
oscillator, RTC, and the RTC temperature compensation are powered by the VBAT_RTC pin. SLP mode
can be exited only by a system power-up event or one of the wake methods described in
3.4 Wake Up
Behavior.
If the SLEEP bit is asserted when V3P3SYS pin power is present (i.e., while in MSN mode), the 71M654x
enters SLP mode, resetting the internal WAKE signal, at which point the 71M654x begins the standard
wake from sleep procedures as described in
3.4 Wake Up
Behavior.
When power is restored to the V3P3SYS pin, the 71M654x transitions from SLP mode to MSN mode and
the MPU PC (Program Counter) is initialized to 0x0000. At this point, the XRAM is in an undefined state,
but non-volatile I/O RAM locations are preserved (the shaded locations in
Table 76
are non-volatile).