Intel manual Deferred Bus-cycle Mode 80C196NU Only, Demultiplexed System Bus Timing 80C196NU

Models: Microcontroller 80C196NU 8XC196NP

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8XC196NP, 80C196NU USER’S MANUAL

 

 

 

TCHCL

TCLCL

T

 

TCLLH

TLLCH

TCHWH

 

CLKOUT

 

 

 

 

 

 

 

TLHLH

 

 

 

 

TWHLH

 

 

 

 

TRHLH

TLHLL

ALE

 

 

 

 

 

 

 

TRHRL

 

TRLCL

 

 

TRHDZ

 

T

T

RLRH

TRHAX

 

AVRL

 

 

 

RD#

 

 

 

 

 

 

TCHDV

 

 

TRLDV

 

 

 

TAVDV

 

 

 

 

TSLDV

 

 

 

AD15:0

 

 

Valid

 

(read)

 

 

 

 

 

 

 

TWLCL

 

 

TWHQX

 

TAVWL

TWLWH

TWHAX

 

WR#

 

 

 

 

AD15:0

TQVWH

 

 

 

 

Valid

 

(write)

 

 

 

 

 

 

 

 

 

 

TWHBX,TRHBX

 

BHE#, INST

 

 

 

 

A19:0

 

 

 

 

CSx#

 

 

 

 

 

 

 

 

T0012-02

Figure 13-23. Demultiplexed System Bus Timing (80C196NU)

13.9.1 Deferred Bus-cycle Mode (80C196NU Only)

The 80C196NU offers a deferred bus cycle mode. This bus mode (enabled by CCR1.5; see Figure 13-7 on page 13-16) reduces bus contention when using the 80C196NU in demultiplexed mode with slow memories. As shown in Figure 13-24, a delay of 2t occurs in the first bus cycle follow- ing a chip-select output change and the first write cycle following a read cycle.

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Page 297
Image 297
Intel 8XC196NP, Microcontroller manual Deferred Bus-cycle Mode 80C196NU Only, Demultiplexed System Bus Timing 80C196NU