
Advanced Notebook I/O for ISA or LPC Designs
Datasheet
SMSC SIO10N268
Page 115
Rev. 0.5 (03-24-05)
DATASHEET
BIT 5 PCD - PARALLEL CONTROL DIRECTION
Parallel Control Direction is not valid in printer mode.
In printer mode, the direction is always out
regardless of the state of this bit. In bi-directional, EPP or ECP mode, 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).
Bits 6 and 7 during a read are a low level, and cannot be written.
8.10.1.4 EPP Address Port
ADDRESS OFFSET = 03H
The EPP Address Port is located at an offset of '03H' from the base address. The address register is
cleared at initialization by RESET. During a WRITE operation, the contents of the internal data bus DB0-
DB7 are buffered (non inverting) and output onto the PD0 - PD7 ports. An LPC I/O write cycle causes an
EPP ADDRESS WRITE cycle to be performed, during which the data is latched for the duration of the EPP
write cycle. During a READ operation, PD0 - PD7 ports are read. An LPC I/O read cycle causes an EPP
ADDRESS READ cycle to be performed and the data output to the host CPU, the deassertion of
ADDRSTB latches the PData for the duration of the read cycle. This register is only available in EPP
mode.
8.10.1.5 EPP Data Port 0
ADDRESS OFFSET = 04H
The EPP Data Port 0 is located at an offset of '04H' from the base address. The data register is cleared at
initialization by RESET. During a WRITE operation, the contents of the internal data bus DB0-DB7 are
buffered (non inverting) and output onto the PD0 - PD7 ports. An LPC I/O write cycle causes an EPP
DATA WRITE cycle to be performed, during which the data is latched for the duration of the EPP write
cycle. During a READ operation, PD0 - PD7 ports are read. An LPC I/O read cycle causes an EPP READ
cycle to be performed and the data output to the host CPU, the deassertion of DATASTB latches the
PData for the duration of the read cycle. This register is only available in EPP mode.
8.10.1.6 EPP Data Port 1
ADDRESS OFFSET = 05H
The EPP Data Port 1 is located at an offset of '05H' from the base address. Refer to EPP DATA PORT 0
for a description of operation. This register is only available in EPP mode.
8.10.1.7 EPP Data Port 2
ADDRESS OFFSET = 06H
The EPP Data Port 2 is located at an offset of '06H' from the base address. Refer to EPP DATA PORT 0
for a description of operation. This register is only available in EPP mode.
8.10.1.8 EPP Data Port 3
ADDRESS OFFSET = 07H
The EPP Data Port 3 is located at an offset of '07H' from the base address. Refer to EPP DATA PORT 0
for a description of operation. This register is only available in EPP mode.