NEC Network Controller uPD98502 - Manual (Page 122)

CHAPTER 2 V R 4120A
122 Preliminary User’s Manual S15543EJ1V0UM
2.4.5.5 Wired register (6)
The Wired register is a read/write register that specifies the lower boundary of the random entry of the TLB as
shown in Figure 2-38. Wired entries cannot be overwritten by a TLBWR instruction. They can, however, be
overwritten by a TLBWI instruction. Random entries can be overwritten by both instructions.
Figure 2-38. Positions Indicated by Wired Register
0
31
Value in the Wired register
Range of Wired
entries
Range specified by
the Random register
The Wired register is set to 0 upon Cold Reset. Writing this register also sets the Random register to the value of
its upper bound (see Section 2.4.5.2 Random register (1)). Figure 2-39 shows the format of the Wired register.
Figure 2-39. Wired Register
4 5 0 31
0 Wired
27 5
Wired : TLB wired boundary
0
: RFU. Write 0 in a write operation. When this field is read, 0 is read.