Intel N2820 FH8065301616603 Data Sheet
Product codes
FH8065301616603
Datasheet
53
Mapping Address Spaces
Processor writes to the 64 KB (each) PROM ‘E’ and ‘F’ segments (E0000h–EFFFFh and
F0000h–FFFFFh) always target DRAM. The BMISC register is used to direct CPU core
reads in these two segments to DRAM or the IO fabric (MMIO).
F0000h–FFFFFh) always target DRAM. The BMISC register is used to direct CPU core
reads in these two segments to DRAM or the IO fabric (MMIO).
CPU core accesses to the 128 KB VGA/CSEG range (A0000h–BFFFFh) can target DRAM
or the IO fabric (MMIO). The target is selected with the BMISC.ABSEGINDRAM register.
or the IO fabric (MMIO). The target is selected with the BMISC.ABSEGINDRAM register.
4.1.1.3
Additional Mappings
There are two additional mappings available in the Processor Transaction Router:
•
SMM range
•
Non-snoop range
SMI handlers running on a CPU core execute out of SMM memory. To protect this
memory from non-CPU core access, the SMM Range (BSMMRRL-BSMMRRH) may be
programmed anywhere in low or high DRAM space (1 MB aligned). This range will only
allow accesses from the CPU cores.
memory from non-CPU core access, the SMM Range (BSMMRRL-BSMMRRH) may be
programmed anywhere in low or high DRAM space (1 MB aligned). This range will only
allow accesses from the CPU cores.
To prevent snoops of the CPU cores when DMA devices access a specific memory
region, the Non-Snoopable Memory range (BNOCACHE.Lower-BNOCACHE.Upper)
can be programmed anywhere in physical address space. This range is enabled via the
BNOCACHECTL register’s enable bit (BNOCACHECTL.Enable).
region, the Non-Snoopable Memory range (BNOCACHE.Lower-BNOCACHE.Upper)
can be programmed anywhere in physical address space. This range is enabled via the
BNOCACHECTL register’s enable bit (BNOCACHECTL.Enable).
Figure 5.
Physical Address Space – SMM and Non-Snoop Mappings
64 GB
Physical Address
Space
BNOCACHE.Upper...
BNOCACHE.Lower...
0
Non-Snoopable
Memory
Low or High DRAM in
Physical Space
BSMMRRH (SMM Range Hi)
BSMMRRL (SMM Range Lo)
SMM Range