Intel Pentium 4 641 HH80552PG0882M Manuale Utente

86

The Enhanced HALT Snoop State is used in conjunction with the new Enhanced HALT state. If 
Enhanced HALT state is not enabled in the BIOS, the default Snoop State entered will be the 
HALT Snoop State. Refer to the sections below for details on HALT Snoop State, Grant Snoop 
State and Enhanced HALT Snoop State.

The processor will respond to snoop transactions on the FSB while in Stop-Grant state or in HALT 
Power Down state. During a snoop transaction, the processor enters the HALT:Grant Snoop state. 
The processor will stay in this state until the snoop on the FSB has been serviced (whether by the 
processor or another agent on the FSB). After the snoop is serviced, the processor will return to the 
Stop-Grant state or HALT Power Down state, as appropriate.

The Enhanced HALT Snoop State is the default Snoop State when the Enhanced HALT state is 
enabled via the BIOS. The processor will remain in the lower bus ratio and VID operating point of 
the Enhanced HALT state.

While in the Enhanced HALT Snoop State, snoops are handled the same way as in the HALT 
Snoop State. After the snoop is serviced the processor will return to the Enhanced HALT Power 
Down state.

§