Yamaha YMF744B (DS-1S) 34h: Capability Register Pointer, 3Ch: Interrupt Li ne, 3Dh: Interrupt Pi n, 3Eh: Minimum Grant

YMF744B
February 3, 1999
-17-
34h: Capability Register Pointer
Read Only
Default: 50h
Access Bus Width: 8, 16, 32-bit
b7 b6 b5 b4 b3 b2 b1 b0
Capability Register Point er
b[7:0] ..........Capability Register Pointer
This register indicates the offset address of the Capabilities register in the PCI Configuration register
when 58-59h: ACPI Mode register, ACPI bit is “0”. DS-1S provides PCI Bus Power Management
registers as the capabilities. The Power Management registers are mapped to 50h - 57h in the PCI
Configuration register, and this register indicates “50h”.
When ACPI bit is “1”, this register indicates “00h”.
3Ch: Interrupt Li ne
Read / Write
Default: 00h
Access Bus Width: 8, 16, 32-bit
b7 b6 b5 b4 b3 b2 b1 b0
Interrupt Li ne
b[7:0] ..........Interrupt Line
This register indicates the interrupt channel that INTA# is assigned to.
3Dh: Interrupt Pi n
Read Only
Default: 01h
Access Bus Width: 8, 16, 32-bit
b7 b6 b5 b4 b3 b2 b1 b0
Interrupt Pin
b[7:0] ..........Interrupt Pin
DS-1S supports INTA# only. This register is hardwired to 01h.
3Eh: Minimum Grant
Read Only
Default: 05h
Access Bus Width: 8, 16, 32-bit
b7 b6 b5 b4 b3 b2 b1 b0
Minimum Grant
b[7:0] ..........Minimum Grant
This register indicates the length of the burst period required by DS-1S.
This register is hardwired to 05h.