ZHDU139A November 2022 – July 2026 DRA821U , DRA821U-Q1 , TPS6594-Q1
ACTIVE 或 RETENTION 状态均可转换为 STANDBY 状态。若要保持在 STANDBY 任务状态,而不进入硬件状态 LP_STANDBY,则必须将 LP_STANDBY_SEL 位清零。
当 ENABLE 引脚变为低电平时,TO_STANDBY 序列会被触发。当 ENABLE 引脚再次变为高电平时,目标状态取决于 STARTUP_DEST 位。对于 TPS65941515,必须将 STARTUP_DEST 设置为 ACTIVE 状态。I2C_0 触发条件也会触发 TO_STANDBY 序列。从 I2C_0 触发时,PMIC 可以通过 GPIO4 或 RTC 定时器或警报触发以返回到 ACTIVE 状态。本例中使用 I2C_0 触发条件来进入 STANDBY 状态,并使用 GPIO4 来进入 ACTIVE 状态。
Write 0x48:0xC3:0x00:0xF7 // LP_STANDBY_SEL=0
Write 0x48:0x7D:0xC0:0x3F // Mask NSLEEP bits
Write 0x48:0x34:0xC0;0x3F // Set GPIO4 to WKUP1 (goes to ACTIVE state)
Write 0x48:0x64:0x08:0xF7 // clear interrupt of GPIO4
Write 0x48:0x4F:0x00:0xF7 // unmask interrupt for GPIO4 falling edge
Write 0x48:0x85:0x01:0xFE // set I2C_0 trigger, trigger TO_STANDBY sequence
After the GPIO4 has gone low and the PMIC has 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 0x48:0x64:0x08:0xF7 // clear interrupt of GPIO4