Renesas SH7781 User Manual

Page 178

Advertising
background image

7. Memory Management Unit (MMU)

Rev.1.00 Jan. 10, 2008 Page 148 of 1658
REJ09B0261-0100

(b)

P1 Area

The P1 area does not allow address translation using the TLB but can be accessed using the
cache.

Regardless of whether the MMU is enabled or disabled, clearing the upper 3 bits of an address
to 0 gives the corresponding physical address. Whether or not the cache is used is determined
by the CCR setting. When the cache is used, switching between the copy-back method and the
write-through method for write accesses is specified by the CB bit in CCR.

(c)

P2 Area

The P2 area does not allow address translation using the TLB and access using the cache.

Regardless of whether the MMU is enabled or disabled, clearing the upper 3 bits of an address
to 0 gives the corresponding physical address.

(d)

P4 Area

The P4 area is mapped onto the internal resource of this LSI. This area except the store queue
and on-chip memory areas does not allow address translation using the TLB. This area cannot
be accessed using the cache. The P4 area is shown in detail in figure 7.4.

H'E000 0000

H'E400 0000

H'F000 0000

H'F100 0000

H'F200 0000

H'F300 0000

H'F400 0000

H'F500 0000

H'F600 0000

H'F700 0000

H'F800 0000

H'FC00 0000

H'FFFF FFFF

Store queue

Reserved area

Reserved area

On-chip memory area

Instruction cache address array

Instruction cache data array

Instruction TLB address array

Instruction TLB data array

Operand cache address array

Operand cache data array

Unified TLB and PMB address array

Unified TLB and PMB data array

Reserved area

Control register area

H'E500 0000
H'E600 0000

Figure 7.4 P4 Area

Advertising