PC87413 datasheet(169/257 Pages) NSC

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9.0 System Wake-Up Control (SWC) (Continued)

Revision 1.2

169

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Figure 49. Dual Control Functions

9.2.5

Power Management Signals

The SWC generates two Power Management signals: ONCTL, for the VDD power supply control, and PWBTOUT, which is

used by an external ACPI controller. These signals are based on the external and internal events, each with its status and

enable bits in the SWC module (including GPIOE). ONCTL and the PWBTOUT are generated according to the current sleep

state.

Special Power Management functions, either required by the ACPI Specification or inherited from the Legacy Power Man-

agement, also affect the ONCTL and PWBTOUT outputs. These functions are described in Section 9.2.6.

Power Supply Control (ONCTL)

Each active external or internal event (including GPIOE) sets a status bit in the GPE1_STS_0 to GPE1_STS_3 registers.

Three events (Power button, Sleep button and RTC alarm) each have an additional status bit in the PM1b_STS_HIGH reg-

ister. Their behavior is described in the SCI Interrupt section (page 168).

ONCTL generation is independent of the enable bits in the GPE1_EN_0 to GPE1_EN_3 registers. It is also independent of

the three additional enable bits in the PM1b_EN_HIGH register (for Power button, Sleep button and RTC alarm events).

ONCTL is not affected by the Watchdog Status bit (WDO_EVT_STS).

ONCTL is turned off (inactive: ONCTL = high level) according to the current sleep states, S3I and S45 (S12 is the active

state for the PC8741x device and does not inﬂuence ONCTL; see Section 9.2.3 on page 167). These current sleep states

are decoded from the value of the SLP_TYPx field of the PM1b_CNT_HIGH register (for EXT_ST_SELECT = 0 in the

SLP_ST_CFG register) or from the levels of the SLPS3 and SLPS5 signals (for EXT_ST_SELECT = 1 in the SLP_ST_CFG

current state is generated by a low-level signal at PWBTIN, overriding the decoded sleep states.

When the PC8741x device enters the S45 state, it turns the VDD power supply Off by setting ONCTL = 1. The state of the

VDD power supply (On or Off) in S3I state depends on the setting of the S3I_VDD_ON bit in the SLP_ST_CFG register (see

Section 9.3.31 on page 200).

If the PC8741x device is the ACPI controller of the system (EXT_ST_SELECT = 0 in the SLP_ST_CFG register), ONCTL is

turned On by an active wake-up event. This is possible only if the event is enabled for wake-up (in the WK_ST_EN register)

in the current sleep state.

Each external or internal event has its own Wake-Up State Enable register (WK_ST_EN), which is accessed by the software

writing its index value (see Table 48 on page 179) into the WKUPSEL field of the Wake-Up Event Select register

(WK_EVT_SEL; see Section 9.3.2). The currently accessed WK_ST_EN register selects the current sleep states for which

Enable

GPE1_STS_2/3

Status

Set

Enable

Status

Set

Reset

GPE1_STS_2/3

PM1b_STS_HIGH

PM1b_EN_HIGH

Detected Event

Disable

ACPI_CFG

Interrupt

SCI

State S0

Only for

Power Button Event

From Other

Enabled Events

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