AMD Geode SC2200 - Manual (Page 292)

304 AMD Geode™ SC2200 Processor Data Book
Core Logic Module - USB Controller Registers - PCIUSB 32580B
1 EmulationInterrupt (Read Only). This bit is a static decode of the emulation interrupt condition.
0 EmulationEnable. When set to 1 the HC is enabled for legacy emulation and will decode accesses to I/O registers 60h
and 64h and generate IRQ1 and/or IRQ12 when appropriate. The HC also generates an emulation interrupt at appropriate
times to invoke the emulation software.
Note: This register is used to enable and control the emulation hardware and report various status information.
Offset 104h-107h HceInput Register (R/W) Reset Value = 000000xxh
31:8 Reserved. Read/Write 0s.
7:0 InputData. This register holds data written to I/O ports 60h and 64h.
Note: This register is the emulation side of the legacy Input Buffer register.
Offset 108h-10Bh HceOutput Register (R/W) Reset Value = 000000xxh
31:8 Reserved. Read/Write 0s.
7:0 OutputData. This register hosts data that is returned when an I/O read of port 60h is performed by application software.
Note: This register is the emulation side of the legacy Output Buffer register where keyboard and mouse data is to be written by soft-
ware.
Offset 10Ch-10Fh HceStatus Register (R/W) Reset Value = 00000000h
31:8 Reserved. Read/Write 0s.
7 Parity. Indicates parity error on keyboard/mouse data.
6 Timeout. Used to indicate a timeout.
5 AuxOutputFull. IRQ12 is asserted whenever this bit is set to 1 and OutputFull is set to 1 and the IRQEn bit is set.
4 Inhibit Switch. This bit reflects the state of the keyboard inhibit switch and is set if the keyboard is NOT inhibited.
3 CmdData. The HC will set this bit to 0 on an I/O write to port 60h and on an I/O write to port 64h the HC will set this bit to 1.
2 Flag. Nominally used as a system flag by software to indicate a warm or cold boot.
1 InputFull. Except for the case of a Gate A20 sequence, this bit is set to 1 on an I/O write to address 60h or 64h. While this
bit is set to 1 and emulation is enabled, an emulation interrupt condition exists.
0 OutputFull. The HC will set this bit to 0 on a read of I/O port 60h. If IRQEn is set and AuxOutputFull is set to 0 then an
IRQ1 is generated as long as this bit is set to 1. If IRQEn is set and AuxOutputFull is set to 1 then and IRQ12 will be gen-
erated a long as this bit is set to 1. While this bit is 0 and CharacterPending in HceControl is set to 1, an emulation inter-
rupt condition exists.
Note: This register is the emulation side of the legacy Status register.
Table 6-42. USB_BAR+Memory Offset: USB Controller Registers (Continued)
Bit Description