LPC47M182 datasheet(97/223 Pages) SMSC

97 / 223 page

Advanced I/O Controller with Motherboard GLUE Logic

Datasheet

SMSC LPC47M182

Revision 1.8 SMSC/Non-SMSC Register Sets (02-24-05)

DATASHEET

7.4.2

Status Port

ADDRESS OFFSET = 01H

The Status Port is located at an offset of ‘01H’ from the base address. The contents of this register are

latched for the duration of a read cycle. The bits of the Status Port are defined as follows:

BIT 0 TMOUT - TIME OUT

This bit is valid in EPP mode only and indicates that a 10 usec time out has occurred on the EPP bus. A

logic O means that no time out error has occurred; a logic 1 means that a time out error has been

detected. This bit is cleared by a RESET. If the TIMEOUT_SELECT bit (bit 4 of the Parallel Port Mode

the TMOUT status bit. Writing a zero to this bit has no effect. If the TIMEOUT_SELECT bit (bit 4 of the

Parallel Port Mode Register 2, 0xF1 in Serial Port Logical Device Configuration Registers) is ‘1’, the

TMOUT bit is cleared on the trailing edge of a read of the EPP Status Register.

BITS 1, 2 - are not implemented as register bits, during a read of the Printer Status Register these bits are

a low level.

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 SLT - 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 - ACKNOWLEDGE

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.

7.4.3

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.

LPC47M182 Datasheet(PDF) 97 Page - SMSC Corporation