AMD-K6 AMD [Advanced Micro Devices], AMD-K6 Datasheet - Page 130

• Manufacturer Part Number: AMD-K6
• Description: AMD-K6 Processor
• Manufacturer: AMD [Advanced Micro Devices]

AMD-K6
Sampled
5.43
Summary
Driven
112
®
Processor Data Sheet
SMIACT# (System Management Interrupt Active)
See “System Management Mode (SMM)” on page 193 for more
details regarding SMM.
SMI# is sampled and latched as a falling edge-sensitive signal.
SMI# is sampled on every clock edge but is not recognized until
the next instruction boundary. If SMI# is to be recognized on
the instruction boundary associated with a BRDY#, it must be
sampled asserted a minimum of three clock edges before the
BRDY# is sampled asserted. If it is asserted synchronously, it
can be asserted for a minimum of one clock. If it is asserted
asynchronously, it must have been negated for a minimum of
two clocks followed by an assertion of a minimum of two clocks.
A second assertion of SMI# while in SMM is latched but is not
recognized until the SMM service routine is exited.
Output
The processor acknowledges the assertion of SMI# with the
assertion of SMIACT# to indicate that the processor has
entered System Management Mode (SMM). The system logic
can use SMIACT# to enable SMM memory. See “SMI# (System
Management Interrupt)” on page 111 for more details.
See “System Management Mode (SMM)” on page 193 for more
details regarding SMM.
The processor asserts SMIACT# after the last BRDY# of the last
pending bus cycle is sampled asserted (including all pending
write cycles) and after EWBE# is sampled asserted. SMIACT#
remains asserted until after the last BRDY# of the last pending
bus cycle associated with exiting SMM is sampled asserted.
SMIACT# remains asserted during any flush, internal snoop, or
writeback cycle due to an inquire cycle.
Preliminary Information
Signal Descriptions
20695H/0—March 1998
Chapter 5