w83877atd Winbond Electronics Corp America, w83877atd Datasheet - Page 100
![no-image](/images/no-image-200.jpg)
w83877atd
Manufacturer Part Number
w83877atd
Description
Winbond I/o
Manufacturer
Winbond Electronics Corp America
Datasheet
1.W83877ATD.pdf
(191 pages)
- Current page: 100 of 191
- Download datasheet (882Kb)
4.3.13 ECP Operation
The host must negotiate on the parallel port to determine if the peripheral supports the ECP protocol
before ECP operation. After negotiation, it is necessary to initialize some of the port bits. The
following are required:
ECP address/RLE bytes or data bytes may be sent automatically by writing the ecpAFifo or ecpDFifo,
respectively.
Mode Switching
Software will execute P1284 negotiation and all operation prior to a data transfer phase under
programmed I/O control (mode 000 or 001). Hardware provides an automatic control line handshake,
moving data between the FIFO and the ECP port only in the data transfer phase (mode 011 or 010).
If the port is in mode 000 or 001, it may switch to any other mode. If the port is not in mode 000 or
001,
When in extended forward mode, the software should wait for the FIFO to be empty before switching
back to mode 000 or 001. In ECP reverse mode the software waits for all the data to be read from the
FIFO before changing back to mode 000 or 001.
Command/Data
ECP mode allows the transfer of normal 8-bit data or 8-bit commands. In the forward direction,
normal data are transferred when HostAck is high and an 8-bit command is transferred when HostAck
is low. The most significant bits of the command indicate whether it is a run-length count (for
compression) or a channel address.
In the reverse direction, normal data are transferred when PeriphAck is high and an 8-bit command is
transferred when PeriphAck is low. The most significant bit of the command is always zero.
Data Compression
The W83877ATF supports run length encoded (RLE) decompression in hardware and can transfer
compressed data to a peripheral. Note that odd (RLE) compression in hardware is not supported. In
order to transfer data in ECP mode, the compression count is written to the ecpAFifo and the data
byte is written to the ecpDFifo.
4.3.14 FIFO Operation
The FIFO threshold is set in configuration register 5. All data transfers to or from the parallel port can
proceed in DMA or Programmed I/O (non-DMA) mode, as indicated by the selected mode. The FIFO
is used by selecting the Parallel Port FIFO mode or ECP Parallel Port Mode. After a reset, the FIFO
is disabled.
(a) Set direction = 0, enabling the drivers.
(b) Set strobe = 0, causing the nStrobe signal to default to the deasserted state.
(c) Set autoFd = 0, causing the nAutoFd signal to default to the deasserted state.
(d) Set mode = 011 (ECP Mode)
it can only be switched into mode 000 or 001. The direction can be changed only in mode 001.
- 96 -
Publication Release Date: April 1998
W83877ATF
Version 0.51
Related parts for w83877atd
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![W83877](/images/no-image3.png)
Part Number:
Description:
Winbond I/O
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83l784r](/images/no-image3.png)
Part Number:
Description:
Winbond H/w Monitoring Ic
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83627thg](/images/no-image3.png)
Part Number:
Description:
Winbond Lpc I/o
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83601r](/images/no-image3.png)
Part Number:
Description:
Winbond Smbus Gpi/o
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83977atf](/images/no-image3.png)
Part Number:
Description:
Winbond I/o
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83194br-sd](/images/no-image3.png)
Part Number:
Description:
Winbond Clock Generator For Intel P4 Springdale Series Chipset
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83194br-603](/images/no-image3.png)
Part Number:
Description:
Winbond Clock Generator For Intel P4 Springdale Series Chipset
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83194br-619](/images/no-image3.png)
Part Number:
Description:
Winbond Clock Generator For Intel P4 Springdale Series Chipset P4 Springdale Series Chipset
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83194br-b](/images/no-image3.png)
Part Number:
Description:
Winbond Clock Generator For Intel P4 845 Series Chipset
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83195bg-341](/images/no-image3.png)
Part Number:
Description:
Winbond Clock Generator For Via P4/kt Series Chipset
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83l784r](/images/no-image3.png)
Part Number:
Description:
Winbond H/w Monitoring Ic
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83627thg](/images/no-image3.png)
Part Number:
Description:
Winbond Lpc I/o
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83601r](/images/no-image3.png)
Part Number:
Description:
Winbond Smbus Gpi/o
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![w83977atf](/images/no-image3.png)
Part Number:
Description:
Winbond I/o
Manufacturer:
Winbond Electronics Corp America
Datasheet:
![W90210F](/images/no-image3.png)
Part Number:
Description:
Pa-risc Embedded Controller
Manufacturer:
Winbond Electronics Corp America
Datasheet: