W83977EF Winbond Electronics Corp America, W83977EF Datasheet - Page 64

• Manufacturer Part Number: W83977EF
• Description: Description = W83877TF Plus Kbc, GP I/O, Wake-Up, Power Fail Resume ;; Package = QFP 128
• Manufacturer: Winbond Electronics Corp America

The system microprocessor can read the contents of the printer control latch by reading the printer
control swapper. Bit definitions are as follows:
Bit 7, 6: These two bits are a logic one during a read. They can be written.
Bit 5: Direction control bit
Bit 4: A 1 in this position allows an interrupt to occur when
Bit 3: A 1 in this bit position selects the printer.
Bit 2: A 0 starts the printer (50 microsecond pulse, minimum).
Bit 1: A 1 causes the printer to line-feed after a line is printed.
Bit 0: A 0.5 microsecond minimum high active pulse clocks data into the printer. Valid data must be
The address port is available only in EPP mode. Bit definitions are as follows:
5.2.3
5.2.4
When this bit is a logic 1, the parallel port is in input mode (read); when it is a logic 0, the
parallel port is in output mode (write). This bit can be read and written. In SPP mode, this bit is
invalid and fixed at zero.
present for a minimum of 0.5 microseconds before and after the strobe pulse.
EPP Address Port
Printer Control Latch and Printer Control Swapper
7
1
7
6
1
6
5
5
4
3
4
-58 -
2
3
1
2
0
ACK#
1
STROBE
AUTO FD
INIT#
SLCT IN
IRQ ENABLE
DIR
0
changes from low to high.
Publication Release Date: April 2003
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
W83977EF
Revision 1.1