AMD-K6 datasheet(113/346 Pages) AMD

113 / 346 page

Chapter 5

Signal Descriptions

20695H/0—March 1998

AMD-K6® Processor Data Sheet

Preliminary Information

5.20

EWBE# (External Write Buffer Empty)

Input

Summary

The system logic can negate EWBE# to the processor to indicate

that its external write buffers are full and that additional data

cannot be stored at this time. This causes the processor to delay

the following activities until EWBE# is sampled asserted:

The commitment of write hit cycles to cache lines in the

modified state or exclusive state in the processor’s cache

The decode and execution of an instruction that follows a

currently-executing serializing instruction

The assertion or negation of SMIACT #

The entering of the Halt state and the Stop Grant state

Negating EWBE # does not prevent the completion of any type

of cycle that is currently in progress.

Sampled

The processor samples EWBE# on each clock edge that BRDY #

is sampled asserted during all memory write cycles (except

writeback cycles), I/O write cycles, and special bus cycles.

If EWBE# is sampled negated, it is sampled on every clock edge

until it is asserted, and then it is ignored until BRDY # is

sampled asserted in the next write cycle or special cycle.

AMD-K6 Datasheet(PDF) 113 Page - Advanced Micro Devices