如節(jié) 5.3.9 所示，MCU 已斷電，因此必須在進(jìn)入保持狀態(tài)前配置從保持狀態(tài)到僅 MCU 或運(yùn)行狀態(tài)的轉(zhuǎn)換。與僅 MCU 狀態(tài)類似，必須為 PMIC 設(shè)置 I2C_7 觸發(fā)條件。本例中使用 TPS6594133A 上的 GPIO4 來從保持狀態(tài)喚醒器件并進(jìn)入運(yùn)行狀態(tài)。

Write 0x48:0x34:0xC0:0x3F // Set GPIO4 to WKUP1 (goes to ACTIVE state) 
Write 0x48:0x64:0x08:0xF7 // clear interrupt of gpio4, write to clear 
Write 0x48:0x4F:0x00:0xF7 // unmask interrupt for GPIO4 falling edge 
Write 0x48:0x86:0x00:0xFC // trigger the TO_RETENTION power sequence 
After the GPIO4 has gone low and the PMIC has returned to the ACTIVE state 
Write 0x48:0x86:0x03:0xFC // Set NSLEEPx bits for ACTIVE state 
Write 0x48:0x64:0x08:0xF7 // clear interrupt of gpio4 

本例中使用 TPS6594133A RTC 計(jì)時器來從保持狀態(tài)喚醒器件并進(jìn)入運(yùn)行狀態(tài)。

Write 0x48:0xC3:0x01:0xFE // Enable Crystal 
Write 0x48:0xC5:0x05:0xF8 // minute timer, enable TIMER interrupts 
Write 0x48:0xC2:0x01:0xFE // start timer, if the timer values are non-zero clear before starting 
Write 0x48:0x86:0x00:0xFC // trigger the TO_RETENTION power sequence 
After the RTC Timer interrupt has occurred and the PMIC has returned to the ACTIVE state 
Write 0x48:0x86:0x03:0xFC // Set NSLEEPx bits for ACTIVE state 
Write 0x48:0xC5:0x00:0xFB // disable timer interrupt, clear bit 2 
Write 0x48:0xC4:0x00:0xDF // clear timer interrupt, clear bit 5.