Figure 64. basic internal and external bus cycles, Figure 6-4 shows internal and external bus cycles – Intel 386 User Manual

Page 125

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Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL

6-12

Figure 6-4 shows internal and external bus cycles.

Figure 6-4. Basic Internal and External Bus Cycles

State

A25:1, BHE#

BLE#, D/C#

M/IO#

W/R#

ADS#

NA#

D15:0

RD#

WR#

BS8#

LOCK#

T1

T2

T1

T2

T1

T2

Ti

T1

T2

Cycle 1

Nonpipelined

External

(Write)

[Late Ready]

Cycle 2

Nonpipelined

Internal

(Read)

Cycle 3

Nonpipelined

Internal

(Write)

[Early Ready]

Cycle 4

Nonpipelined

External

(Read)

REFRESH#

LBA#

CLK2

CLKOUT

Valid 1

Valid 2

Valid 3

Out 1

Valid 1

Valid 2

Valid 3

In

2

Out 3

In

4

Idle

Cycle

Idle

Cycle

Idle

Cycle

Ti

Ti

End Cycle 1

End Cycle 2

End Cycle 3

READY#

End Cycle 4

Valid 4

Valid 4

A2486-03

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