SLVUCI5 april 2023 AM6526 , AM6528 , AM6548 , TPS6594-Q1
STANDBY can be entered from ACTIVE, MCU ONLY, or the RETENTION states. To stay in the mission state of STANDBY and not enter the hardware state LP_STANDBY the LP_STANDBY_SEL bit must be cleared.
When the ENABLE pin goes low, the TO_STANDBY sequence is triggered. When the ENABLE pin goes high again, the destination state is dependent upon the STARTUP_DEST bits. The TO_STANDBY sequence is also triggered by the I2C_0 trigger. When triggered from I2C_0 the PMIC can be triggered to return to either the ACTIVE or MCU ONLY states by GPIO8 or and RTC timer or alarm. In this example, I2C_0 trigger is used to enter the STANDBY state and the GPIO8 is used to enter the ACTIVE state.
Write 0x48:0xC3:0x00:0xF7 // LP_STANDBY_SEL=0
Write 0x48:0x7D:0xC0:0x3F // Mask NSLEEP bits
Write 0x48:0x38:0xC0;0x3F // Set GPIO4 to WKUP1 (goes to ACTIVE state)
Write 0x48:0x64:0x80:0x7F // clear interrupt of GPIO8
Write 0x48:0x4F:0x00:0x7F // unmask interrupt for GPIO8 falling edge
Write 0x48:0x85:0x01:0xFE // set I2C_0 trigger, trigger TO_STANDBY sequence
After the GPIO8 has gone low and the PMICs have returned to the ACTIVE state
Write 0x48:0x7D:0x00:0x3F // unmask NSLEEP bits
Write 0x48:0x86:0x03:0xFC // Set NSLEEPx bits for ACTIVE state
Write 0x48:0x64:0x80:0x7F // clear interrupt of GPIO8