VR4102 datasheet(161/701 Pages) NEC

161 / 701 page

CHAPTER 6 EXCEPTION PROCESSING

161

6.3.2 BadVAddr Register (8)

The Bad Virtual Address (BadVAddr) register is a read-only register that saves the most recent virtual address

that failed to have a valid translation, or that had an addressing error. Figure 6-2 shows the format of the BadVAddr

Caution

This register saves no information after a bus error exception, because it is not an address

error exception.

Figure 6-2. BadVAddr Register Format

(a) 32-bit mode

BadVAddr

(b) 64-bit mode

BadVAddr

BadVAddr:

Most recent virtual address for which an addressing error occurred, or for which address

translation failed

6.3.3 Count Register (9)

The read/write Count register acts as a timer. It is incremented in synchronization with the MasterOut clock,

regardless of whether instructions are being executed, retired, or any forward progress is actually made through the

pipeline.

This register is a free-running type.

When the register reaches all ones, it rolls over to zero and continues

counting. This register is used for self-diagnostic test, system initialization, or the establishment of inter-process

synchronization.

Figure 6-3 shows the format of the Count register.

Figure 6-3. Count Register Format

Count

Count: 32-bit up-date count value that is compared with the value of the Compare register

VR4102 Datasheet(PDF) 161 Page - NEC