Specifications

222 AMD Geodeā„¢ GeodeROM Functional Specification
System Management Mode Software
32087C
The EVENT_IO_TRAP and EVENT_IO_TIMEOUT events are not completely general-purpose in the Geode GX1 proces-
sor and single chip (SC1100, SC1200, SC1201, SC2200, and SC3200) processors. The intention is to provide a common
interface to the variety of I/O traps and timers supported by the hardware. If the I/O base does not match one of the traps or
time-outs directly supported by the South Bridge, the System Manager attempts to use the user-defined trap hardware.
However, the user-defined traps are a limited resource and there are range restrictions, so it is possible for a registration
request to be rejected. The traps and time-outs for which there is direct hardware support (in Geode GX1 processor and
single chip processors) are listed in Table 15-4. In the Geode GX processor and later processors, I/O trapping is general-
purpose and Table 15-4 does not apply.
Example of usage:
SYS_REGISTER_EVENT(EVENT_IO_TRAP, 0x1F6,0x02, Priority); // Trap Primary IDE
Table 15-4. Hardware Supported Traps and Time-outs
1
1. Applies to Geode GX1 processor and single chip processors only.
Device I/O Base Address Range (Bytes) Timeout Units
Port B (A20M/reset) 92h 1 N/A
Game port 200h 2 N/A
Audio 220h/240h/260h/280h
300h/330h (MIDI)
00h/C0h (DMA)
10h
2
10h each
N/A
LPT1 & LPT2 378h/278h 8 each
COM2 2F8h 8 N/A
COM4 2E8h 8 N/A
Primary IDE 1F6h 2 Seconds
Secondary IDE 176h 2 Seconds
Floppy 3F5h or 375h 1 Seconds
LPT1/LPT2/COM1-4 Standard PC/AT addresses 8 each Seconds
Keyboard/Mouse 60h/64h (62h/66h) N/A Seconds
PCI 0CFCh 4 N/A