AMD SC1201, SC1200 Second Millisecond, Re-trigger General Purpose Timer 1 on Floppy Disk Activity

Core Logic Module - Bridge, GPIO, and LPC Registers - Function 0 32579B

Table 6-29. F0: PCI Header/Bridge Configuration Registers for GPIO and LPC Support (Continued)

Bit	Description
Index 89h		General Purpose Timer 1 Control Register (R/W)	Reset Value: 00h
7	General Purpose Timer 1 TImebase. Selects timebase for General Purpose Timer 1 (F0 Index 88h).
	0:	1 second.
	1:	1 millisecond.
6	Re-trigger General Purpose Timer 1 on User Defined Device 3 (UDEF3) Activity.
	0:	Disable.
	1:	Enable.
	Any access to the configured (memory or I/O) address range for UDEF3 (configured in F0 Index C8h and CEh) reloads
	General Purpose Timer 1.
5	Re-trigger General Purpose Timer 1 on User Defined Device 2 (UDEF2) Activity.
	0:	Disable.
	1:	Enable.
	Any access to the configured (memory or I/O) address range for UDEF2 (configured in F0 Index C4h and CDh) reloads
	General Purpose Timer 1.
4	Re-trigger General Purpose Timer 1 on User Defined Device 1 (UDEF1) Activity.
	0:	Disable.
	1:	Enable.
	Any access to the configured (memory or I/O) address range for UDEF1 (configured in F0 Index C0h and CCh) reloads
	General Purpose Timer 1.
3	Re-trigger General Purpose Timer 1 on Keyboard or Mouse Activity.
	0:	Disable.
	1:	Enable.
	Any access to the keyboard or mouse I/O address range listed below reloads General Purpose Timer 1:
		— Keyboard Controller: I/O Ports 060h/064h.
		— COM1: I/O Port 3F8h-3FFh (if F0 Index 93h[1:0] = 10 this range is included).
		— COM2: I/O Port 2F8h-2FFh (if F0 Index 93h[1:0] = 11 this range is included).
2	Re-trigger General Purpose Timer 1 on Parallel/Serial Port Activity.
	0:	Disable.
	1:	Enable.
	Any access to the parallel or serial port I/O address range listed below reloads the General Purpose Timer 1:
		— LPT1: I/O Port 3BCh-3BEh.
		— LPT2: I/O Port 378h-37Fh.
		— 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.
1	Re-trigger General Purpose Timer 1 on Floppy Disk Activity.
	0:	Disable.
	1:	Enable.
	Any access to the floppy disk drive address ranges listed below reloads General Purpose Timer 1:
		— Primary floppy disk: I/O Port 3F2h-3F5h, 3F7h
		— Secondary floppy disk: I/O Port 372h-375h, 377h
	The active floppy disk drive is configured via F0 Index 93h[7].
0	Re-trigger General Purpose Timer 1 on Primary Hard Disk Activity.
	0:	Disable.
	1:	Enable.
	Any access to the primary hard disk address range selected in F0 Index 93h[5], reloads General Purpose Timer 1.

AMD Geode™ SC1200/SC1201 Processor Data Book 211