OX9162
OXFORD SEMICONDUCTOR LTD.
DSR[2]: INT#
DCR[3]: nSLIN#
logic 0 Þ A parallel port interrupt is pending.
logic 1 Þ No parallel port interrupt is pending.
logic 0 Þ Set SLIN# output to high (inactive).
logic 1 Þ Set SLIN# output to low (active).
This bit is activated (set low) on a rising edge of the ACK#
pin. It is de-activated (set high) after reading the DSR.
During an EPP address or data cycle the ADDRSTB# pin is
driven by the EPP controller, otherwise it is inactive.
DSR[3]: ERR#
logic 0 Þ The ERR# input is low.
logic 1 Þ The ERR# input is high.
DCR[4]: ACK Interrupt Enable
logic 0 Þ ACK interrupt is disabled.
logic 1 Þ ACK interrupt is enabled.
DSR[4]: SLCT
DCR[5]: DIR
logic 0 Þ The SLCT input is low.
logic 1 Þ The SLCT input is high.
logic 0 Þ PD port is output.
logic 1 Þ PD port is input.
DSR[5]: PE
logic 0 Þ The PE input is low.
logic 1 Þ The PE input is high.
This bit is overridden during an EPP address or data cycle,
when the direction of the port is controlled by the bus
access (read/write)
DCR[7:6]: Reserved
These bits are reserved and always set to “00”.
DSR[6]: ACK#
logic 0 Þ The ACK# input is low.
logic 1 Þ The ACK# input is high.
6.3.5 EPP address register ‘EPPA’
DSR[7]: nBUSY
logic 0 Þ The BUSY input is high.
logic 1 Þ The BUSY input is low.
EPPA is located at offset 003h in lower block, and is only
used in EPP mode. A byte written to this register will be
transferred to the peripheral as an EPP address by the
hardware. A read from this register will transfer an address
from the peripheral under hardware control.
6.3.4 Device control register ‘DCR’
DCR is located at offset 002h in the lower block. It is a
read-write register which controls the state of the peripheral
inputs and enables the peripheral interrupt. When reading
this register, bits 0 to 3 reflect the actual state of STB#,
AFD#, INIT# and SLIN# pins respectively. When in EPP
mode, the WRITE#, DATASTB# AND ADDRSTB# pins are
driven by the EPP controller, although writes to this register
will override the state of the respective lines.
6.3.6 EPP data registers ‘EPPD1-4’
The EPPD registers are located at offset 004h-007h of the
lower block, and are only used in EPP mode. Data written
or read from these registers is transferred to/from the
peripheral under hardware control.
6.3.7 ECP Data FIFO
DCR[0]: nSTB#
logic 0 Þ Set STB# output to high (inactive).
logic 1 Þ Set STB# output to low (active).
Hardware transfers data from this 16 bytes deep FIFO to
the peripheral when DCR(5) = ‘0’. When DCR(5) = ‘1’
hardware transfers data from the peripheral to this FIFO.
During an EPP address or data cycle the WRITE# pin is
driven by the EPP controller, otherwise it is inactive.
6.3.8 Test FIFO
Used by the software in conjunction with the full and empty
flags to determine the depth of the FIFO and interrupt
levels.
DCR[1]: nAFD#
logic 0 Þ Set AFD# output to high (inactive).
logic 1 Þ Set AFD# output to low (active).
6.3.9 Configuration A register
During an EPP address or data cycle the DATASTB# pin is
driven by the EPP controller, otherwise it is inactive.
ECR[7:5] must be set to ‘111’ to access this register.
Interrupts generated will always be level, and the ECP port
only supports an impID of ‘001’.
DCR[2]: INIT#
logic 0 Þ Set INIT# output to low (active).
logic 1 Þ Set INIT# output to high (inactive).
Data Sheet Revision 1.1 PRELIMINARY
Page 23
OXFORD [ OXFORD SEMICONDUCTOR ]
