37C672 datasheet(82/173 Pages) SMSC

82 / 173 page

Enhanced Super I/O Controller with Fast IR

Datasheet

SMSC FDC37C672

Page 82

Rev. 10-29-03

DATASHEET

BIT 3 nERR - nERROR

The level on the nERROR input is read by the CPU as bit 3 of the Printer Status Register. A logic 0

means an error has been detected; a logic 1 means no error has been detected.

BIT 4 SLCT - PRINTER SELECTED STATUS

The level on the SLCT input is read by the CPU as bit 4 of the Printer Status Register. A logic 1 means

the printer is on line; a logic 0 means it is not selected.

BIT 5 PE - PAPER END

The level on the PE input is read by the CPU as bit 5 of the Printer Status Register. A logic 1 indicates a

paper end; a logic 0 indicates the presence of paper.

BIT 6 nACK - nACKNOWLEDGE

The level on the nACK input is read by the CPU as bit 6 of the Printer Status Register. A logic 0 means

that the printer has received a character and can now accept another. A logic 1 means that it is still

processing the last character or has not received the data.

BIT 7 nBUSY - nBUSY

The complement of the level on the BUSY input is read by the CPU as bit 7 of the Printer Status Register.

A logic 0 in this bit means that the printer is busy and cannot accept a new character. A logic 1 means that

it is ready to accept the next character.

CONTROL PORT

ADDRESS OFFSET = 02H

The Control Port is located at an offset of '02H' from the base address. The Control Register is initialized

by the RESET input, bits 0 to 5 only being affected; bits 6 and 7 are hard wired low.

BIT 0 STROBE - STROBE

This bit is inverted and output onto the nSTROBE output.

BIT 1 AUTOFD - AUTOFEED

This bit is inverted and output onto the nAUTOFD output. A logic 1 causes the printer to generate a line

feed after each line is printed. A logic 0 means no autofeed.

BIT 2 nINIT - nINITIATE OUTPUT

This bit is output onto the nINIT output without inversion.

BIT 3 SLCTIN - PRINTER SELECT INPUT

This bit is inverted and output onto the nSLCTIN output. A logic 1 on this bit selects the printer; a logic 0

means the printer is not selected.

BIT 4 IRQE - INTERRUPT REQUEST ENABLE

The interrupt request enable bit when set to a high level may be used to enable interrupt requests from the

Parallel Port to the CPU. An interrupt request is generated on the IRQ port by a positive going nACK

input. When the IRQE bit is programmed low the IRQ is disabled.

37C672 Datasheet(PDF) 82 Page - SMSC Corporation