XR16C872CQ EXAR [Exar Corporation], XR16C872CQ Datasheet - Page 43

• Manufacturer Part Number: XR16C872CQ
• Description: DUAL UART WITH 1284 PARALLEL PORT AND PLUG-AND-PLAY CONTROLLER
• Manufacturer: EXAR [Exar Corporation]

“EPP MODE” SIGNAL DESCRIPTIONS
EPP Mode Data Transfer Cycle
1. Program executes an I/O write cycle to EPP Data Port-4.
2. The Write# line is asserted and the data is output to the parallel port.
3. The DataStb# is asserted, since Write# is asserted low.
4. The port waits for the acknowledge from the peripheral, Write# deasserted.
5. The DataStr# is deasserted and EPP cycle ends.
6. Write# is asserted low to indicate that the next cycle may begin.
Signal
name
STROBE#
AUTOFD#
SELCTIN#
INIT#
ACK#
BUSY
PE
SELECT
ERR#
PD0-PD7
Rev. 1.00
Signal
Type
O
O
O
O
O
I
I
I
I
I
User defined
User defined
User defined
EPP mode
AD0-AD7
DataStb#
AddrStb#
Reset#
Write#
Name
Wait#
Intr#
DISCONTINUED
Active low. Indicates a write operation, high for a read cycle
Description
Active low. Indicates a Data-Read or Data-Write operation is in
process.
Active low. Indicates an Address-Read or Address-Write opera
tion is in process.
Active low. Peripheral reset.
Peripheral interrupt. Used to generate an interrupt to the host.
Handshake signal. When low it indicates that is okay to start a cycle,
when high it indicates that it is okay to end the cycle.
Not used.
Not used.
Not used.
Bi-directional address / data lines.
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XR16C872