TMPR4951B datasheet(95/256 Pages) TOSHIBA

95 / 256 page

Chapter 4 Memory Management System

4-13

32-bit Kernel Mode, Kernel Space 1 (kseg1)

In Kernel mode, when KX = 0 in the Status register and the most-significant three bits of the 32-

bit virtual address are 1012, 32-bit kseg1 virtual address space is selected; it is the 2

29 bytes (512

Mbytes) kernel physical space. References to kseg1 are not mapped through the TLB; the physical

address selected is defined by subtracting 0xA000 0000 from the virtual address. Caches are

disabled for accesses to these addresses, and physical memory (or memory-mapped I/O device

registers) are accessed directly.

32-bit Kernel Mode, Supervisor Space (ksseg)

In Kernel mode, when KX

= 0 in the Status register and the most-significant three bits of the 32-

bit virtual address are 1102, the ksseg virtual address space is selected; it is the current 2

29 bytes

(512 Mbytes) supervisor virtual space. The virtual address is extended with the contents of the 8-

bit ASID field to form a unique virtual address.

32-bit Kernel Mode, Kernel Space 3 (kseg3)

In Kernel mode, when KX = 0 in the Status register and the most-significant three bits of the 32-

bit vital address are 1112, the kseg3 virtual address space is selected; it is the current 2

29 bytes (512

Mbytes-4 Mbytes) kernel virtual space. The virtual address is extended with the contents of the 8-

bit ASID field to form a unique virtual address.

Note:

These is the 4 Mbytes Reserved area, begin at virtual address 0xFF00_0000 and runs

through 0xFF3F_FFFF.

TMPR4951B Datasheet(PDF) 95 Page - Toshiba Semiconductor