Writing Device Drivers

SBus Physical Address Space

The following table shows the physical address space layout of the Sun UltraSPARC 2 computer. A physical address on the UltraSPARC 2 model consists of 41 bits. The 41-bit physical address space is further broken down into multiple 33-bit address spaces identified by PA(40:33).

Table A–1 Device Physical Space in the Ultra 2


33-bit Space 



0x000000000 - 0x07FFFFFFF

2 Gbytes main memory 

0x80 – 0xDF 

Reserved on Ultra 2

Reserved on Ultra 2 


Processor 0

Processor 0 


Processor 1

Processor 1 

0xE2 – 0xFD 

Reserved on Ultra 2

Reserved on Ultra 2 


0x000000000 - 0x1FFFFFFFF

UPA Slave (FFB) 


0x000000000 - 0x0FFFFFFFF

System I/O space 


0x100000000 - 0x10FFFFFFF

SBus Slot 0 


0x110000000 - 0x11FFFFFFF

SBus Slot 1 


0x120000000 - 0x12FFFFFFF

SBus Slot 2 


0x130000000 - 0x13FFFFFFF

SBus Slot 3 


0x1D0000000 - 0x1DFFFFFFF

SBus Slot D 


0x1E0000000 - 0x1EFFFFFFF

SBus Slot E 


0x1F0000000 - 0x1FFFFFFFF

SBus Slot F