YMF724F
54-55h: Power Management Control / Status
Read / Write
Default: 0000h
Access Bus Width: 8, 16, 32-bit
b15
b14
b13
b12
b11
b10
b9
-
b8
-
b7
-
b6
-
b5
-
b4
-
b3
-
b2
-
b1
b0
-
-
-
-
-
-
PS
b[1:0] ..........PS: Power State
These bits determine the power state of DS-1. DS-1 supports the following power states:
“0”:
“1”:
“2”:
“3”:
D0
D1
(not supported)
D2
D3hot
When the power state is changed from D3hot to D0, DS-1 resets the PCI Configuration register 00-3Fh.
DS-1 transits to D0 Uninitialized state.
Though the power state of this register is changed, the power consumption of DS-1 is not changed. To
support low power, Windows driver controls DS-1 Power Control Register.
DS-1 can support the power state of D0, D1, D2 and D3 with ACPI. In this case, set ACPI bit (58-59h:
ACPI Mode Register) to “1” to disable Capabilities of PCI Bus Power Management.
58-59h: ACPI Mode
Read / Write
Default: 0000h
Access Bus Width: 8, 16, 32-bit
b15
b14
b13
b12
b11
b10
b9
-
b8
-
b7
-
b6
-
b5
-
b4
-
b3
-
b2
-
b1
-
b0
-
-
-
-
-
-
ACPI
b0................ACPI: ACPI Mode Select
This bit select either PCI Bus Power Management or ACPI Mode for power management of DS-1.
“0”: PCI Bus Power Management is used. CAP bit (06-07h: Status Register) and Capabilities Pointer
(34h) are enabled. (default)
“1”: ACPI Mode is used. CAP bit and Capabilities Pointer are hardwired “0”, and disabled.
January 14, 1999
-26-
YAMAHA [ YAMAHA CORPORATION ]
