825318253·5

MODE 0: Interrupt on Terminal Count

MODE 3: Square Wave Generator

CLOCK

CLOCK

iI

WRn~OUTPUT (n = 4)

 

I

 

 

I

 

4

3

2

1

0

OUTPUT (n = 51

OUTPUT (INTERRUPT)

l'I

In =41 I---t--n --+]

II

II

WRm~

 

I

I

 

GATE------------~:L___Jr~I--------

5

4

2

1

OUTPUT (INTERRUPTI

 

 

 

(m "'51 '--'

 

 

 

A

 

 

 

A+B=-m

 

 

MODE 1: Programmable One·Shot

 

 

MODE 4: Software Triggered Strobe

 

 

 

 

 

 

CLOCK

 

 

 

 

 

 

TRIGGER

~

 

________~~~2__'~~

OUTPUT

 

 

 

 

 

 

 

4

3

2

1

 

 

 

 

 

 

 

OUTPUT

~i~~~~-f-----------

 

 

 

 

 

 

 

TRIGGER~

GATE

-------~~~---------

 

4i_~3__:2~4__3~~2__'~j---------

OUTPUT

 

______~4_______4~_3__2

~1__;0

---- , .

 

 

 

OUTPUT

 

 

 

 

 

u -

 

 

 

 

 

 

 

 

 

 

MODE 2: Rate Generator

 

 

 

MODE 5: Hardware Triggered Strobe

 

 

 

 

 

 

CLOCK

 

 

 

 

 

 

 

 

 

 

 

GATE ------Ir -----

 

 

 

 

 

 

 

4

3

2

1

0

 

 

 

 

 

 

OUTPUT (n • 41

 

 

 

 

L.J

 

 

 

 

 

 

GATE~

 

 

 

 

 

 

 

4343210

 

 

 

 

 

 

OUTPUT In • 41

 

 

 

 

W

Figure 5. 8253 Timing Diagrams

9-11

AFN-00745A-06

Page 326
Image 326
Intel mcs-48 manual =41 I---t--n --+, Mode 2 Rate Generator