82378ZB Datasheet, PDF (52/137 Pages) Intel Corporation – SYSTEM I/O APIC(SIO.A) AND

82378ZB (SIO) AND 82379AB (SIO.A)
E
negated until the stop grant special cycle has been generated by the CPU. Thus, from the time that STPCLK# is
asserted until the stop grant cycle is returned, the occurrence of subsequent break events are latched in the
SIO/SIO.A.
NOTE
INIT is always enabled as a break event. However, INIT only causes a break event after a stop grant
special cycle has been received. If INIT is asserted while STPCLK# is active and then negated before the
stop grant cycle is received, INIT does not cause a break event.
Bit
Description
31
Fast-Off SMI Enable (FSMIEN): 1=Enable; 0=Disable. System and Break events.
30
82378ZB: Reserved.
82379AB: Fast-Off Interrupt Enable (FINTREN). 1=Enable; 0=Disable. Break event only.
29
Fast-Off NMI Enable (FNMIEN): 1=Enable; 0=Disable. System and Break events.
28
Reserved.
27
82378ZB: Reserved.
82379AB: Fast-Off COM Enable (FCOMEN): 1=Enable; 0=Disable. System events only.
26
82378ZB: Reserved.
82379AB: Fast-Off LPF Enable (FLPTEN): 1=Enable; 0=Disable. System events only.
25
82378ZB: Reserved.
82379AB: Fast-Off Drive Enable (FDRVEN): 1=Enable; 0=Disable. System events only.
24
82378ZB: Reserved.
82379AB: Fast-Off DMA Enable (FDMAEN): 1=Enable; 0=Disable. System events only.
23:16 Reserved.
15:3 Fast-Off IRQ[15:3] Enable (FIRQ[15:3]EN): 1=Enable; 0=Disable. System and Break events.
2
Reserved.
1:0
Fast-Off IRQ[1:0] Enable (FIRQ[1:0]EN): 1=Enable; 0=Disable. System and Break events.
3.1.32. FTMR—FAST OFF TIMER REGISTER
Address Offset:
Default Value:
Attribute:
A8h
0Fh
Read/Write
The Fast-Off Timer is used to indicate (through an SMI) that the system has been idle for a pre-programmed
period of time. The Fast-Off Timer consists of a count-down timer and the value programmed into this register is
loaded into the Fast-Off Timer when an enabled system event occurs. When the timer expires, an SMI special
cycle is generated. When the Fast-Off Timer is enabled (Bit 3=0 in the SMICNTL Register), the timer counts
down from the value loaded into this register. The count time interval is one minute. When the Fast-Off Timer
reaches 00h, an SMI is generated and the timer is re-load with the value programmed into this register. If an
enabled system event occurs before the Fast-Off Timer reaches 00h, the Fast-Off Timer is re-loaded with the
value in this register.
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