w83977atg Winbond Electronics Corp America, w83977atg Datasheet - Page 99

• Manufacturer Part Number: w83977atg
• Description: W83877tf Plus Kbc, Gp I/o, Wake-up, Fir, Cir, Pb-free
• Manufacturer: Winbond Electronics Corp America

Bit 7: This bit reflects the complement of the Busy input.
Bit 6: This bit reflects the nAck input.
Bit 5: This bit reflects the PError input.
Bit 4: This bit reflects the Select input.
Bit 3: This bit reflects the nFault input.
Bit 2-0: These three bits are not implemented and are always logic one during a read.
8.3.4
The bit definitions are as follows:
Bit 6, 7: These two bits are logic one during a read and cannot be written.
Bit 5: This bit has no effect and the direction is always out if mode = 000 or mode = 010. Direction is
Bit 4: Interrupt request enable. When this bit is set to a high level, it may be used to enable interrupt
Bit 3: This bit is inverted and output to the SLIN output.
Bit 2: This bit is output to the INIT output.
Bit 1: This bit is inverted and output to the AFD output.
Bit 0: This bit is inverted and output to the STB output.
8.3.5
This mode is defined only for the forward direction. The standard parallel port protocol is used by a
hardware handshake to the peripheral to transmit bytes written or DMAed from the system to this
FIFO. Transfers to the FIFO are byte aligned.
Device Control Register (DCR)
cFifo (Parallel Port Data FIFO) Mode = 010
valid in all other modes.
0
1
requests from the parallel port to the CPU due to a low to high transition on the ACK input.
0
1
the parallel port is in output mode.
the parallel port is in input mode.
The printer is not selected.
The printer is selected.
7
1
6
1
5
4
3
- 91 -
2
W83977ATF/W83977ATG
1
0
strobe
autofd
nInit
SelectIn
ackIntEn
Direction
Publication Release Date: May 2006
Revision 0.6