Advanced I/O Controller with Motherboard GLUE Logic
Datasheet
7.12.2 DEVICE STATUS REGISTER (dsr)
ADDRESS OFFSET = 01H
The Status Port is located at an offset of ‘01H’ from the base address. Bits0 - 2 are not implemented as
register bits, during a read of the Printer Status Register these bits are a low level. The bits of the Status
Port are defined as follows:
BIT 3 nFault
The level on the nFault input is read by the CPU as bit 3 of the Device Status Register.
BIT 4 Select
The level on the Select input is read by the CPU as bit 4 of the Device Status Register.
BIT 5 PError
The level on the PError input is read by the CPU as bit 5 of the Device Status Register. Printer Status
Register.
BIT 6 nAck
The level on the nAck input is read by the CPU as bit 6 of the Device Status Register.
BIT 7 nBusy
The complement of the level on the BUSY input is read by the CPU as bit 7 of the Device Status Register.
7.12.3 DEVICE CONTROL REGISTER (dcr)
ADDRESS OFFSET = 02H
The Control Register is located at an offset of ‘02H’ from the base address. The Control Register is
initialized to zero 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 - INITIATE OUTPUT
This bit is output onto the nINITP output without inversion.
BIT 3 SELECTIN
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 ackIntEn - 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 due to a low to high transition on the nACK input. Refer to the description
of the interrupt under Operation, Interrupts.
BIT 5 DIRECTION
If mode=000 or mode=010, this bit has no effect and the direction is always out regardless of the state of
this bit. In all other modes, Direction is valid and a logic 0 means that the printer port is in output mode
(write); a logic 1 means that the printer port is in input mode (read).
Revision 1.8 SMSC/Non-SMSC Register Sets (02-24-05)
106
SMSC LPC47M182
DATASHEET
SMSC [ SMSC CORPORATION ]
