w83977atf Winbond Electronics Corp America, w83977atf Datasheet - Page 195

• Manufacturer Part Number: w83977atf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

Modes 000 (SPP) and 001 (PS/2) (Data Port)
During a write operation, the Data Register latches the contents of the data bus on the rising edge of
the input. The contents of this register are output to the PD0-PD7 ports. During a read operation,
ports PD0-PD7 are read and output to the host. The bit definitions are as follows:
Mode 011 (ECP FIFO-Address/RLE)
A data byte written to this address is placed in the FIFO and tagged as an ECP Address/RLE. The
hardware at the ECP port transmits this byte to the peripheral automatically. The operation of this
register is defined only for the forward direction. The bit definitions are as follows:
These bits are at low level during a read of the Printer Status Register. The bits of this status register
are defined as follows:
5.3.2 Data and ecpAFifo Port
5.3.3 Device Status Register (DSR)
7
6
7
7
5
6
6
4
5
5
3
4
4
2
3
3
- 91 -
1
2
2
1
0
1
1
1
0
0
1
Address/RLE
Address or RLE
nFault
Select
PError
nAck
nBusy
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
Publication Release Date:April 1998
W83977ATF
PRELIMINARY
Revision 0.52