AMD-K6-2E Datasheet, PDF (141/332 Pages) Advanced Micro Devices – AMD-K6™-2E Embedded Processor

22529B/0—January 2000
Preliminary Information
AMD-K6™-2E Processor Data Sheet
5.45
STPCLK# (Stop Clock)
Pin Attribute
Pin Location
Summary
Input, Internal Pullup
V-34
The assertion of STPCLK# causes the processor to enter the
Stop Grant state, during which the processor’s internal clock is
stopped. From the Stop Grant state, the processor can
subsequently transition to the Stop Clock state, in which the
bus clock CLK is stopped. Upon recognizing STPCLK#, the
processor performs the following actions, in the order shown:
1. Flushes its instruction pipelines
2. Completes all pending and in-progress bus cycles
3. Acknowledges the STPCLK# assertion by executing a Stop
Grant special bus cycle (see Table 23 on page 132)
4. Stops its internal clock after BRDY# of the Stop Grant
special bus cycle is sampled asserted and after EWBE# is
sampled asserted (if EWBE# is masked off, then entry into
the Stop Grant state is not affected by EWBE#)
5. Enters the Stop Clock state if the system logic stops the bus
clock CLK (optional)
Sampled
See “Clock Control States” on page 247 for more details
regarding clock control.
STPCLK# is sampled as a level-sensitive input on every clock
edge but is not recognized until the next instruction boundary.
System logic can drive the signal either synchronously or
asynchronously. If it is asserted asynchronously, it must be
asserted for a minimum pulse width of two clocks.
STPCLK# must remain asserted until recognized, which is
indicated by the completion of the Stop Grant special cycle.
Chapter 5
Signal Descriptions
123