MIPS R10000 Microprocessor User's Manual - SGI TechPubs Library

258 Chapter 14.
14.16 WatchLo (18) and WatchHi (19) Registers
WatchHi and WatchLo are 32-bit read/write registers which contain a physical
address of a doubleword location in main memory. If enabled, any attempt to read
or write this location causes a Watch exception. This feature is used for debugging.
Bits 7:0 of the WatchHi register contain bits 39:32 of the trap physical address,
shown in Figure 14-18. The WatchLo register contains physical address bits 31:3.
The remaining bits of the register are ignored on write and read as zero.
Table 14-16 describes the WatchLo and WatchHi register fields.
31
31
WatchLo Register
PAddr0
29 1 1 1
WatchHi Register
Figure 14-18 WatchLo and WatchHi Register Formats
Table 14-16 WatchHi and WatchLo Register Fields
Field Description
PAddr1 Bits 39:32 of the physical address
PAddr0 Bits 31:3 of the physical address
R Trap on load references if set to 1
W Trap on store references if set to 1
0 Ignored on write and read as zero.
3 2 1 0
Version 2.0 of January 29, 1997 MIPS R10000 Microprocessor User's Manual
0
24 8
R W
8 7
0
0 PAddr1