SC1200UCL-266 AMD (ADVANCED MICRO DEVICES), SC1200UCL-266 Datasheet - Page 212

• Manufacturer Part Number: SC1200UCL-266
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of SC1200UCL-266

• Lead Free Status / Rohs Status: Not Compliant

212
Index 8Ah
Index 8Bh
Index 8Ch
Index 8Dh
Table 6-29. F0: PCI Header/Bridge Configuration Registers for GPIO and LPC Support (Continued)
Bit
7:0
1:0
7:0
7:0
7
6
5
4
3
2
Description
GPT2_COUNT. This field represents the load value for General Purpose Timer 2. This value can represent either an 8-bit or
16-bit counter (configured in F0 Index 8Bh[5]). It is loaded into the counter when the timer is enabled (F0 Index 83h[1] = 1).
Once the timer is enabled and a transition occurs on GPIO7, the timer is re-loaded.
The counter is decremented with each clock of the configured timebase (1 msec or 1 sec selected at F0 Index 8Bh[3]). Upon
expiration of the counter, an SMI is generated and the top level of status is F1BAR0+I/O Offset 00h/02h[9]. The second level
of status is reported at F1BAR0+I/O Offset 04h/06h[1]). Once expired, this counter must be re-initialized by either disabling
and enabling it, or by writing a new count value in this register. See Section 6.2.10.3 "Peripheral Power Management" on
page 164 for a discussion on the limitations of producing count error with small values.
For GPIO7 to act as the reload for this counter, it must be enabled as such (F0 Index 8Bh[2]) and be configured as an input.
(GPIO pin programming is at F0BAR0+I/O Offset 20h and 24h.)
Re-trigger General Purpose Timer 1 (GP Timer 1) on Secondary Hard Disk Activity.
0: Disable.
1: Enable.
Any access to the secondary hard disk address range selected in F0 Index 93h[4] reloads GP Timer 1.
VGA Timer Base. Selects timebase for VGA Timer Register (F0 Index 8Eh).
0: 1 millisecond.
1: 32 microseconds.
General Purpose Timer 2 (GP Timer 2) Shift. GP Timer 2 is treated as an 8-bit or 16-bit timer.
0: 8-bit. The count value is loaded into GP Timer 2 Count Register (F0 Index 8Ah).
1: 16-bit. The value loaded into GP Timer 2 Count Register is shifted left by eight bits, the lower eight bits become zero,
General Purpose Timer 1 (GP Timer 1) Shift. GP Timer 1 is treated as an 8-bit or 16-bit timer.
0: 8-bit. The count value is that loaded into GP Timer 1 Count Register (F0 Index 88h).
1: 16-bit. The value loaded into GP Timer 1 Count Register is shifted left by eight bit, the lower eight bits become zero, and
General Purpose Timer 2 (GP Timer 2) Timebase. Selects timebase for GP Timer 2 (F0 Index 8Ah).
0: 1 second.
1: 1 millisecond.
Re-trigger Timer on GPIO7 Pin Transition. A rising-edge transition on the GPIO7 pin reloads GP Timer 2 (F0 Index 8Ah).
0: Disable.
1: Enable.
For GPIO7 to work here, it must first be configured as an input. (GPIO pin programming is at F0BAR0+I/O Offset 20h and
24h.)
Reserved. Set to 0.
IRQ Speedup Timer Load Value. This field represents the load value for the IRQ speedup timer. It is loaded into the
counter when Suspend Modulation is enabled (F0 Index 96h[0] = 1) and an INTR or an access to I/O Port 061h occurs.
When the event occurs, the Suspend Modulation logic is inhibited, permitting full performance operation of the GX1 module.
Upon expiration, no SMI is generated; the Suspend Modulation begins again. The IRQ speedup timer’s timebase is 1 msec.
This speedup mechanism allows instantaneous response to system interrupts for full-speed interrupt processing. A typical
value here would be 2 to 4 msec.
Video Speedup Timer Load Value. This field represents the load value for the Video speedup timer. It is loaded into the
counter when Suspend Modulation is enabled (F0 Index 96[0] = 1) and any access to the graphics controller occurs. When
a video access occurs, the Suspend Modulation logic is inhibited, permitting full-performance operation of the GX1 module.
Upon expiration, no SMI is generated, and Suspend Modulation begins again. The video speedup timer’s timebase is 1
msec.
This speedup mechanism allows instantaneous response to video activity for full speed during video processing calcula-
tions. A typical value here would be 50 msec to 100 msec.
and this 16-bit value is used as the count for GP Timer 2.
this 16-bit value is used as the count for GP Timer 1.
32579B
General Purpose Timer 2 Control Register (R/W)
General Purpose Timer 2 Count Register (R/W)
Video Speedup Timer Count Register (R/W)
IRQ Speedup Timer Count Register (R/W)
Core Logic Module - Bridge, GPIO, and LPC Registers - Function 0
AMD Geode™ SC1200/SC1201 Processor Data Book
Reset Value: 00h
Reset Value: 00h
Reset Value: 00h
Reset Value: 00h