On Sunday 13 May 2007 10:42, popkonserve wrote:
Geode GX1: IO Recovery Time is 6 clocks
Can anyone interpret this value? Does it mean "Recovery on PCI bus" side? The GX1 processor only has a PCI bus, nothing else.
yes, i can :)
Quote from: "Cyrix MediaGX Databook, October 29, 1998 - Revision 2.0, Cyrix Corporation"
"3.4.1 I/O Address Space The CPU I/O address space is accessed using IN and OUT instructions to addresses referred to as “ports.” The accessible I/O address space is 64KB and can be accessed as 8-bit, 16-bit or 32-bit ports. The MediaGX processor configuration registers reside within the I/O address space at port addresses 22h and 23h and are accessed using the standard IN and OUT instructions."
Index E8h : CCR4 "2:0 IORT(2:0) I/O Recovery Time: Specifies the minimum number of bus clocks between I/O accesses: 000 = No clock delay 100 = 16-clock delay 001 = 2-clock delay 101 = 32-clock delay (default value after reset) 010 = 4-clock delay 110 = 64-clock delay 011 = 8-clock delay 111 = 128-clock delay Cleared to 0 at reset."
My manual say the same. But with the description above it seems it only an internal delay. No used for external accesses. Can you send me this manual, please? Mine is newer and from AMD. It seems in this newer manual many register bits are marked "reserverd", where in the old manuals their real use and function was documented (maybe).
Juergen