Geode鈩?CS5530A
Functional Description
(Continued)
Table 3-19. Parallel/Serial Idle Timer and Trap Related Registers
Bit
Description
Power Management Enable Register 2 (R/W)
Reset Value = 00h
F0 Index 81h
2
Parallel/Serial Idle Timer Enable:
Load timer from Parallel/Serial Port Idle Timer Count Register (F0 Index 9Ch) and gen-
erate an SMI when the timer expires. 0 = Disable; 1 = Enable.
If an access occurs in the address ranges (listed below) the timer is reloaded with the programmed count.
LPT1: I/O Port 378h-37Fh, 778h-77Ah
LPT2: I/O Port 278h-27Fh, 678h-67Ah
COM1: I/O Port 3F8h-3FFh (if F0 Index 93h[1:0] = 10 this range is excluded)
COM2: I/O Port 2F8h-2FFh (if F0 Index 93h[1:0] = 11 this range is excluded)
COM3: I/O Port 3E8h-3EFh
COM4: I/O Port 2E8h-2EFh
Top level SMI status is reported at F1BAR+Memory Offset 00h/02h[0].
Second level SMI status is reported at F0 Index 85h/F5h[2].
F0 Index 82h
2
Power Management Enable Register 3 (R/W)
Reset Value = 00h
Parallel/Serial Trap:
0 = Disable; 1 = Enable.
If this bit is enabled and an access occurs in the address ranges (listed below) an SMI is generated.
LPT1: I/O Port 378h-37Fh, 778h-77Ah
LPT2: I/O Port 278h-27Fh, 678h-67Ah
COM1: I/O Port 3F8h-3FFh (if F0 Index 93h[1:0] = 10 this range is excluded)
COM2: I/O Port 2F8h-2FFh (if F0 Index 93h[1:0] = 11 this range is excluded)
COM3: I/O Port 3E8h-3EFh
COM4: I/O Port 2E8h-2EFh
Top level SMI status is reported at F1BAR+Memory Offset 00h/02h[0].
Second level SMI status is reported at F0 Index 86h/F6h[2].
F0 Index 93h
1
0
Miscellaneous Device Control Register (R/W)
Reset Value = 00h
Mouse on Serial Enable:
Mouse is present on a serial port. 0 = No; 1 = Yes. (Note)
Mouse Port Select:
Selects which serial port the mouse is attached to. 0 = COM1; 1 = COM2. (Note)
Note:
Bits 1 and 0 - If a mouse is attached to a serial port (bit 1 = 1), that port is removed from the serial device list being used to
monitor serial port access for power management purposes and added to the keyboard/mouse decode. This is done because a
mouse, along with the keyboard, is considered an input device and is used only to determine when to blank the screen.
These bits determine the decode used for the Keyboard/Mouse Idle Timer Count Register (F0 Index 9Eh) as well as the Paral-
lel/Serial Port Idle Timer Count Register (F0 Index 9Ch).
F0 Index 9Ch-9Dh
15:0
Parallel / Serial Idle Timer Count Register (R/W)
Reset Value = 0000h
Parallel / Serial Idle Timer Count:
The idle timer loaded from this register is used to determine when the parallel and serial
ports are not in use so that the ports can be power managed. The 16-bit value programmed here represents the period of
inactivity for these ports after which the system is alerted via an SMI. The timer is automatically reloaded with the count
value whenever an access occurs to the parallel (LPT) or serial (COM) I/O address spaces. If the mouse is enabled on a
serial port, that port is not considered here. The timer uses a 1 second timebase.
To enable this timer set F0 Index 81h[2] = 1.
Top level SMI status is reported at F1BAR+Memory Offset 00h/02h[0].
Second level SMI status is reported at F0 Index 85h/F5h[2].
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