Note 1
: These addresses are added to the parallel port base address as selected by configuration register or jumpers.
Note 2
: All addresses are qualified with AEN. Refer to the AEN pin definition.
SMSC DS – LPC47M192
Page 91
Rev. 03/30/05
DATASHEET
Table 43 - Mode Descriptions
MODE
000
001
010
011
100
101
110
111
DESCRIPTION*
SPP mode
PS/2 Parallel Port mode
Parallel Port Data FIFO mode
ECP Parallel Port mode
EPP mode (If this option is enabled in the configuration registers)
Reserved
Test mode
Configuration mode
*Refer to ECR Register Description
DATA and ecpAFifo PORT
ADDRESS OFFSET = 00H
Modes 000 and 001 (Data Port)
The Data Port is located at an offset of ‘00H’ from the base address. The data register is cleared at initialization by
RESET. During a WRITE operation, the Data Register latches the contents of the data bus. The contents of this
register are buffered (non inverting) and output onto the PD0 - PD7 ports. During a READ operation, PD0 - PD7
ports are read and output to the host CPU.
Mode 011 (ECP FIFO - Address/RLE)
A data byte written to this address is placed in the FIFO and tagged as an ECP Address/RLE. The hardware at the
ECP port transmits this byte to the peripheral automatically. The operation of this register is only defined for the
forward direction (direction is 0). Refer to the ECP Parallel Port Forward Timing Diagram, located in the Timing
Diagrams section of this data sheet .
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.