8291

r----'

r ----- ,

I

I

I

I

I DC

I

I PP2

I

I

I

I

I

L ____ J

L ____ J

pon--_--I

F6'" DCl + SOC • LADS

lOY·

r----'

{WITHINtsJ

I

I

 

 

I DT

I

 

I

I

 

L ____ ..J

"'IDY= ATN . EOI

F!gure A,1, 8291 State D!agrams

Appendix B

IEEE 488 TIME VALUES

Time Value

 

 

 

Identifier'

Function (Applies to)

Description

Value

T1

SH

Settling Time for Multiline Messages

<:: 21'st

t2

LC,iC,SH,AH,T,L

Response to ATN

::; 200ns

T3

AH

Interface Message Accept Time t

> 06

t4

T,TE,L,LE,C,CE

Response to IFC or REN False

< 1001's

t5

PP

Response to ATN+EOI

::; 200ns

T6

C

Parallel Poll Execution Time

<:: 21's

T7

C

Controller Delay to Allow Current Talker

<:: 500ns

 

 

to see ATN Message

 

T8

C

Length of IFC or REN False

> 1001's

T9

C

Delay for EOI"

<:: 1.5l'stt

•Time values specified by a lower case t indicate the maximum time allowed to make a state transition. Time values specified by an upper case T indicate the minimum time that a function must remain in a state before exiting.

If three-state drivers are used on the 010, DAV, and EOI lines, T1 may be:

1.2: 1100ns

2.Or 2: 700ns if it is known that within the controller ATN is driven by a three-state driver.

3.Or 2: 500ns for 'allsubsequent bytes following the first sent after each false transition of ATN (the first byte must be sent in accordance with, (1) or (2).

4.Or 2: 350ns for all subsequent bytes following the first sent 'aftereach false transition of ATN under conditions specified in Section 5.2.3 and warning note. See IEEE Standard 488.

t Time required for interface functions to accept, not necessarily respond to interface messages.

{j Implementation independent.

••Delay required for EOI, NDAC, and NRFD signal lines to indic,ate valid slates. tt 2: 600ns for three-state drivers.

9-102

Page 416 Page 418
Page 417
Image 417
Intel mcs-48 manual Settling Time for Multiline Messages 21st, Response to ATN 200ns Interface Message Accept Time t
Page 416 Page 418
Top Page Image Contents