W83787IF Datasheet, PDF (47/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
5.2.1 Data Swapper
The system microprocessor can read the contents of the printer's data latch by reading the data
swapper.
5.2.2 Printer Status Buffer
The system microprocessor can read the printer status by reading the address of the printer status
buffer. The bit definitions are as follows:
76 5 4 321 0
11
TMOUT
ERROR
SLCT
PE
ACK
BUSY
Notes:
Bit 7: This signal is active during data entry, when the printer is off-line during printing, when the print
head is changing position, or during an error state. When this signal is active, the printer is
busy and cannot accept data.
Bit 6: This bit represents the current state of the printer's ACK signal. A 0 means the printer has
received a character and is ready to accept another. Normally, this signal will be active for
approximately 5 microseconds before BUSY stops.
Bit 5: A 1 means the printer has detected the end of paper.
Bit 4: A 1 means the printer is selected.
Bit 3: A 0 means the printer has encountered an error condition.
Bit 1, 2: These two bits are not implemented and are logic one during a read of the status register.
Bit 0: This bit is valid in EPP mode only. It indicates that a 10 µS timeout has occurred on the EPP
bus. A logic 0 means that no timeout error has occurred; a logic 1 means that a timeout error
has been detected. Writing a logic 1 to this bit will clear the timeout status bit; writing a logic 0
has no effect.
5.2.3 Printer Control Latch and Printer Control Swapper
The system microprocessor can read the contents of the printer control latch by reading the printer
control swapper. Bit definitions are as follows:
7 6 5 43 21 0
11
STROBE
AUTO FD
INIT
SLCT IN
IRQ ENABLE
DIR
Notes:
Bit 7, 6: These two bits are a logic one during a read. They can be written.
Bit 5: Direction control bit
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Publication ReleaseDate:Sep 1995
Revision A1