Intel 80386 Xixxxxx Valid, Xixxxx ,XXXXY, ~~~~ Doo¥, BSI6# XXX XXx XXX X .. IXXXXwOO~ J, XXX XXX1

inter			80386
		A TRANSFER REQUIRING TWO
		CYCLES ON 16-81T DATA BUS
IDLE		CYCLE 1			CYCLE 1A			CYCLE 2
	NON-PIPELINED			NON-PIPELINED			NON-PIPELINED
		(READ ---- ! --- READ)						(WRITE)
		PART ONE			PART TWO
Ti	T1	T2	T2	TI	T2	T2	T1	T2	T2

CLK2 [ -MnILM rmrtJl nILnILnILrtJlnIL

(82384 CLK) [ -VV V V V V V V V V

8EO #. 8El #

8E2 #. 8E3 #

A2- A31. M/IO#. D/C#

[ XIXXXXX VALID I	I	NEGATED DURING	i\	VALID 2
		PART TWO
[ J.lXX.X) X				I
	VALID I			VALID 2

W/R# [ ~~/

ADS#	[	LV		I	V
		N TE: NA# MUST BE NEGATED"---			"---
		HERE TO ALLOW RECOGNITION
		OF ASSERTED BSI6# IN FINAL T2
NA#	[ XIXXXX ,XXXXY		'<X~~~~DOO()(¥		'X~~~~~{ XXXXrY	'( XXX
						~

BUS ~ZE

BSI6# [ )[XXX :XX'x XXX X ).. "IXXXXwOO<~ J, XXX XXX'1/ '\

16-BIT	16-81T
BUS SIZE	BUS SIZE
READY # [ ) XXX)DOOC <XI ~ I IX) 'XY	~I IX 'XI ~

LOCK# [ )( Y.'J.'X'J~ .

DO- D15 [ - ---- ----

D16- D31 [ - --------

Key: On = physical data pin n dn = logical data bit n

VALID I			VALID 2
dO-dl5	---	d16-d31	dO-dl5
-----0--		--0<
			OUT
IGNORED		IGNORED	d16-d31
--_.--0-- ---		--0	OUT
I		I	I

231630-19

Figure 5-15. Asserting 8S16# (one wait state, non-pipelined address)

generated for the two 16-bit bus cycles are closely related to each other. The addresses are the same except 8EO# and 8E1 # are always negated for the second cycle. This is because data on DO-D15 was already transferred during the first 16-bit cycle.

Figures 5-14 and 5-15 show cases where assertion of 8816# requires a second 16-bit cycle for com- plete operand transfer. Figure 5-14 illustrates cycles

without wait states. Figure 5-15 illustrates cycles with one wait state. In Figure 5-15 cycle 1, the bus cycle during which 8816# is asserted, note that NA# must be negated in the T2 state(s) prior to the last T2 state. This is to allow the recognition of 8816# asserted in the final T2 state. The relation of NA# and 8816# is given fully in 5.4.3.4 Pipelined Address, but Figure 5-15 illustrates this only pre- caution you need to know when using 8816# with non-pipelined address.

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