ST78C36/36A

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ECP/EPP PARALLEL PRINTER PORT WITH 16-BYTE FIFO

REV. 5.0.1

4

PRINTER PORT INTERFACE

PD7

PD6

PD5

PD4

PD3

PD2

PD1

PD0

38

37

36

35

34

33

32

31

45

44

43

42

41

40

39

38

I/O

Bi-directional parallel port (three-state) to transfer data in or out of the

ST78C36 parallel port. PD[7:0] are latched during output mode. Output

only for SPP and PPF modes, bi-directional for all other modes.

-STROBE

25

27

O

Data strobe output (internal pull-up / three stated active low). This output

indicates to the printer that valid data is available at the printer port (PD0-

PD7).

-AUTOFDX

26

28

O

Automatic line feed (internal pull-up / three stated active low). When this

signal is low the printer should automatically line feed after each line is

printed.

INIT

27

29

O

Initialize line printer (internal pull-up / three stated active low). When this

signal is low, it causes the printer to be initialized.

-SLCTIN

28

30

O

Line printer select (internal pull-up / three stated active low). When this

signal is low, it selects the printer.

-ERROR

1

57

I

Line printer error (internal pull-up / active low). This is an output from the

printer to indicate an error by holding it low during error condition.

SLCT

2

58

I

Line printer selected (internal pull-up / active high). This is an output from

the printer to indicate that the line printer has been selected.

BUSY

3

59

I

Line printer busy (internal pull-up / active high). An output from the printer

to indicate printer is not ready to accept data.

-ACK

4

60

I

Line printer acknowledge (internal pull-up / active low). This input is

pulsed low by the printer to indicate that data has been accepted success-

fully.

PE

5

61

I

Line printer paper empty (internal pull-up / active high). An output from the

printer to indicate out of paper.

PDIR

21

23

O

Printer port direction indicator. HIGH indicates device is in input mode,

LOW indicates output mode. (ST78C36CJ44 and ST78C36CQ64 only).

SYSTEM SIGNALS

CLOCK/

XTAL1

20

21

I

Crystal oscillator input (ST78C36ACJ44, ST78C36CQ64) or External

clock input (ST78C36CJ44), nominal 24 MHz.

XTAL2

21

22

O

Crystal oscillator output, nominal 24 MHz. ST78C36ACJ44 and

ST78C36CQ64 only.

RESET

24

26

I

System RESET ( active HIGH).

PIN DESCRIPTION

PIN

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PIN

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