ulp: document the need to wait for RTC to be ready for wakeup

This commit is contained in:
Ivan Grokhotkov 2017-12-07 17:11:24 +08:00
parent b6a6973b44
commit ca751648fa
4 changed files with 25 additions and 5 deletions

View file

@ -1830,7 +1830,16 @@
#define RTC_CNTL_SCRATCH7_V 0xFFFFFFFF
#define RTC_CNTL_SCRATCH7_S 0
#define RTC_CNTL_DIAG0_REG (DR_REG_RTCCNTL_BASE + 0xc0)
#define RTC_CNTL_LOW_POWER_ST_REG (DR_REG_RTCCNTL_BASE + 0xc0)
/* RTC_CNTL_RDY_FOR_WAKEUP : R/0; bitpos:[19]; default: 0 */
/*description: 1 if RTC controller is ready to execute WAKE instruction, 0 otherwise */
#define RTC_CNTL_RDY_FOR_WAKEUP (BIT(19))
#define RTC_CNTL_RDY_FOR_WAKEUP_M (BIT(19))
#define RTC_CNTL_RDY_FOR_WAKEUP_V 0x1
#define RTC_CNTL_RDY_FOR_WAKEUP_S 19
/* Compatibility definition */
#define RTC_CNTL_DIAG0_REG RTC_CNTL_LOW_POWER_ST_REG
/* RTC_CNTL_LOW_POWER_DIAG0 : RO ;bitpos:[31:0] ;default: 0 ; */
/*description: */
#define RTC_CNTL_LOW_POWER_DIAG0 0xFFFFFFFF

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@ -573,11 +573,17 @@ Similar considerations apply to ``LD`` and ``ST`` instructions. Consider the fol
- If the SoC is not in deep sleep mode, and ULP interrupt bit (RTC_CNTL_ULP_CP_INT_ENA) is set in RTC_CNTL_INT_ENA_REG register, RTC interrupt will be triggered.
Note that before using WAKE instruction, ULP program may needs to wait until RTC controller is ready to wake up the main CPU. This is indicated using RTC_CNTL_RDY_FOR_WAKEUP bit of RTC_CNTL_LOW_POWER_ST_REG register. If WAKE instruction is executed while RTC_CNTL_RDY_FOR_WAKEUP is zero, it has no effect (wake up does not occur).
**Examples**::
1: WAKE // Trigger wake up
REG_WR 0x006, 24, 24, 0 // Stop ULP timer (clear RTC_CNTL_ULP_CP_SLP_TIMER_EN)
HALT // Stop the ULP program
1: is_rdy_for_wakeup: // Read RTC_CNTL_RDY_FOR_WAKEUP bit
READ_RTC_FIELD(RTC_CNTL_LOW_POWER_ST_REG, RTC_CNTL_RDY_FOR_WAKEUP)
AND r0, r0, 1
JUMP is_rdy_for_wakeup, eq // Retry until the bit is set
WAKE // Trigger wake up
REG_WR 0x006, 24, 24, 0 // Stop ULP timer (clear RTC_CNTL_ULP_CP_SLP_TIMER_EN)
HALT // Stop the ULP program
// After these instructions, SoC will wake up,
// and ULP will not run again until started by the main program.

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@ -130,6 +130,11 @@ edge_detected:
.global wake_up
wake_up:
/* Check if the system can be woken up */
READ_RTC_FIELD(RTC_CNTL_LOW_POWER_ST_REG, RTC_CNTL_RDY_FOR_WAKEUP)
and r0, r0, 1
jump wake_up, eq
/* Wake up the SoC, end program */
wake
halt

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@ -105,7 +105,7 @@ exit:
.global wake_up
wake_up:
/* Check if the system can be woken up */
READ_RTC_REG(RTC_CNTL_DIAG0_REG, 19, 1)
READ_RTC_FIELD(RTC_CNTL_LOW_POWER_ST_REG, RTC_CNTL_RDY_FOR_WAKEUP)
and r0, r0, 1
jump exit, eq