AMD SC3200 manual Wakeup Events Capability

Core Logic Module 32581C

6.2.9.2Sleep States

The SC3200 supports four Sleep states (SL1-SL3) and the Soft Off state (G2/S5). These states are fully compliant with the ACPI specification, revision 1.0.

When the SLP_EN bit (F1BAR1+I/O Offset 0Ch[13]) is set to 1, the SC3200 enters an SLx state according to the SLP_TYPx field (F1BAR1+I/O Offset 0Ch[12:10]). It exits the Sleep state back to the S0 state (C0 state - Full Speed or Throttling, depending on the THT_EN bit) upon an enabled power management event. Table 6-5 on page 157 lists wakeup events from the various Sleep states.

SL1 Sleep State (ACPI S1)

In this state the core processor is in 3V Suspend mode (all its clocks are stopped, including the memory controller and the display controller). The SDRAM is placed in self-refresh mode. All other SC3200 system clocks and PLLs are run- ning. All devices are powered up (PWRCNT[2:1] and ONCTL# are all asserted). See Section 6.2.9.5 "Usage Hints" on page 159.

No reset is performed, when exiting this state. The SC3200 keeps all context in this state. This state corresponds to ACPI Sleep state S1.

SL2 Sleep State (ACPI S1)

In this state, all of the SC3200 clocks are stopped including the PLLs. Selected clocks from the PLLs can be kept run- ning under program control (F0 Index 60h). An exception to this is the CLK32 output signal which keeps toggling and the 32 KHz oscillator itself. The SDRAM is placed in self- refresh mode. The PWRCNT1 pin is de-asserted. The SC3200 itself is powered up. The system designer can

decide which other system devices to power off with the PWRCNT1 pin.

No reset is performed, when exiting this state. The SC3200 keeps all context in this state. This state corresponds to ACPI sleep state S1, with lower power and longer wake time than in SL1.

SL3 Sleep State (ACPI S3)

In this state, the SDRAM is placed in self-refresh mode, and PWRCNT[2:1] are de-asserted. PWRCNT[2:1] should be used to power off most of the system (except for the SDRAM). If the Save-to-RAM feature is used, external cir- cuitry in the SDRAM interface is required to guarantee data integrity. All SC3200 signals powered by VSB, VSBL or VBAT are still functional to allow wakeup and to keep the RTC.

The power-up sequence is performed, when exiting this state. This state corresponds to ACPI Sleep state S3.

SL4 and SL5 Sleep States (ACPI S4 and S5)

The SL4 and SL5 states are similar from the hardware per- spective. In these states, the SC3200 de-asserts PWRCNT[2:1] and ONCTL#. PWRCNT[2:1] and ONCTL# should be used to power off the system. All signals pow-

ered by VSB, VSBL or VBAT are still functional to allow wakeup and to keep the RTC.

While in this state, LED# can be toggled to give visual noti- fication of this state. ACPI Function Control register (F1BAR1+I/O Offset 07h[7:6]) is used to control LED#.

The power-up sequence is performed when exiting this state. This state corresponds to ACPI Sleep states S4 and S5.

Table 6-5. Wakeup Events Capability

Event	S0/C1	S0/C3	SL1	SL2	SL3	SL4, SL5
Enabled Interrupts	Yes	Yes	Yes	-	-	-
SMI according to Table 6-8	Yes	Yes	Yes	-	-	-
SCI according to Table 6-8	Yes	Yes	Yes	-	-	-
GPIO[47:32], GPIO[15:0]	Yes	Yes	Yes	-	-	-
Power Button	Yes	Yes	Yes	Yes	Yes	Yes
Power Button Override	Yes	Yes	Yes	Yes	Yes	Yes
Bus Master Request	Yes1	Yes	Yes	-	-	-
Thermal Monitoring	Yes	Yes	Yes	Yes	Yes	Yes
USB	Yes	Yes	Yes	Yes	-	-
SDATA_IN2 (AC97)	Yes	Yes	Yes	Yes	-	-
IRRX1 (Infrared)	Yes	Yes	Yes	Yes	-	-
GPWIO[2:0]	Yes	Yes	Yes	Yes	Yes	Yes
RI2# (UART2)	Yes	Yes	Yes	Yes	-	-
RTC	Yes	Yes	Yes	Yes	Yes	Yes

1.Temporarily exits state.

AMD Geode™ SC3200 Processor Data Book 157