AMD Geode™ LX Processor/CS5536 Companion Device GeodeROM Porting Guide 27
5
Implementation 40680B
5.0Implementation
5.1 Implementation
The following is a collection of implementation details to consider in the GeodeROM implementation phase.
5.1.1 Clocking
There are two clock inputs to the LX processor: the system PCI clock (SYSREF), used to derive the Core clock, and the
GeodeLink™ clock, used for the memory clock. The Dot clock is used for video display control. The Core and GeodeLink
clocks can be programmed and restarted by reseting the LX processor.
5.1.2 Scratchpad Initialization
The scratchpad is no longer needed either for BLT buffers or by the audio code for variable storage. The scratchpad is not
supported in the LX processor CPU Core.
5.1.3 Post Codes
Post codes are sent out to port 80 throughout GeodeROM. A Post codes list is available in the AMD Geode™ GeodeROM
Functional Specification (publication ID 32087) to help users debug their problems.