GM82C803CN Datasheet, PDF (20/84 Pages) List of Unclassifed Manufacturers – 2.88 MB FDC/ Dual UARTs with FIFO/PIO(EPP/ ECP)/ IDE Interface/ S-IR/ PnP

GM82C803CN
STATUS REGISTER (STR)
This register is located at an offset of 01H from base address and is read-only register. This register can be
accessed in all parallel port modes. The bits of STR are defined as follows:
BIT 0 TIMEOUT
This bit is valid in only EPP mode and indicates that a 10 usec timeout has occurred. A logic 0 means that no
timeout error has occurred. A logic 1 indicates that a timeout error has been detected. This bit can be cleared
by RESET or writing a 1 to this bit. In not EPP mode, this bit is always 0.
BIT 1, 2
These bits are reserved and always 0.
BIT 3 ERROR
This bit reflects the state of the ERROR input pin. A logic 0 means that error has been detected.
BIT 4 SLCT
This bit reflects the state of the SLCT input pin. A logic 1 indicates that printer is on-line. A logic 0 means
printer is not selected.
BIT 5 PE
This bit reflects the state of the PE input pin. A logic 1 indicates that printer is out of paper.
BIT 6 ACK
This bit reflects the state of the ACK input pin. A logic 0 indicates that printer has been received a character
and is ready to accept another.
BIT 7 BUSY
This bit reflects the inverted state of the BUSY input pin. A logic 0 indicates that printer is busy and cannot
accept a new data.
CONTROL REGISTER (CTR)
This register is located at an offset of 02H from base address. The reset value is 00H. This read/write register
provides control of all output signals. This register can be accessed in all parallel port.
BIT 0 STROBE
This bit is inverted of the STROBE pin and controls data strobe to printer.
BIT 1 AUTOFD
This bit is inverted of the AUTOFD pin. A logic 1 causes the printer to generate an automatic line feed at the
end of each line.
BIT 2 INIT
This bit controls INIT pin used to initialize the printer. A logic 0 generates active low pulse to initialize the
printer.
BIT 3 SLCTIN
This bit is inverted of the SLCTIN pin. A logic 1 causes the printer to be selected.
BIT 4 IRQEN
This is the interrupt request enabling bit. When this bit is 1, parallel port interrupt is generated in respond to a
transition of ACK signal from the printer. Otherwise, all interrupts are disabled and all pending interrupts are
cleared.