NEC Network Controller uPD98502 - Manual (Page 132)

CHAPTER 2 V R 4120A
132 Preliminary User’s Manual S15543EJ1V0UM
2.5.3.2 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 2-48 shows the format of the BadVAddr
register.
Caution This register saves no information after a bus error exception, because it is not an address error
exception.
Figure 2-48. BadVAddr Register Format
(a) 32-bit mode
32
0 31
BadVAddr
(b) 64-bit mode
(b) 64-bit mode
64
0 63
BadVAddr
BadVAddr: Most recent virtual address for which an addressing error occurred, or for which address translation
failed.
2.5.3.3 Count register (9)
The read/write Count register acts as a timer. It is incremented in synchronization with the frequencies of
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 2-49 shows the format of the Count register.
Figure 2-49. Count Register Format
32
0 31
Count
Count: 32-bit up-date count value that is compared with the value of the Compare register.