W83L517D Datasheet, PDF (99/138 Pages) Winbond – LPC SUPER I/O

W83L517D
Version 0.6
6.3 Extended Capabilities Parallel (ECP) Port
This port is software and hardware compatible with existing parallel ports, so it may be used as a
standard printer mode if ECP is not required. It provides an automatic high burst-bandwidth channel that
supports DMA for ECP in both the forward (host to peripheral) and reverse (peripheral to host)
directions.
Small FIFOs are used in both forward and reverse directions to improve the maximum bandwidth
requirement. The size of the FIFO is 16 bytes. The ECP port supports an automatic handshake for the
standard parallel port to improve compatibility mode transfer speed.
The ECP port supports run-length-encoded (RLE) decompression (required) in hardware. Compression is
accomplished by counting identical bytes and transmitting an RLE byte that indicates how many times
the next byte is to be repeated. Hardware support for compression is optional.
For more information about the ECP Protocol, refer to the Extended Capabilities Port Protocol and ISA
Interface Standard.
6.3.1 ECP Register and Mode Definitions
NAME
data
ADDRESS
Base+000h
I/O
ECP MODES
R/W
000-001
FUNCTION
Data Register
ecpAFifo
Base+000h
R/W
011
ECP FIFO (Address)
dsr
Base+001h
R
All
Status Register
dcr
Base+002h
R/W
All
Control Register
cFifo
Base+400h
R/W
010
Parallel Port Data FIFO
ecpDFifo
Base+400h
R/W
011
tFifo
Base+400h
R/W
110
ECP FIFO (DATA)
Test FIFO
cnfgA
Base+400h
R
111
Configuration Register A
cnfgB
Base+401h
R/W
111
Configuration Register B
ecr
Base+402h
R/W
All
Extended Control Register
Note: The base addresses are specified by CR23, which are determined by configuration register or
hardware setting.
MODE
DESCRIPTION
000
SPP mode
001
PS/2 Parallel Port mode
010
Parallel Port Data FIFO mode
011
ECP Parallel Port mode
100
EPP mode (If this option is enabled in the CR9 and CR0 to select ECP/EPP mode)
101
Reserved
110
Test mode
111
Configuration mode
Note: The mode selection bits are bit 7-5 of the Extended Control Register.
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Publication Release Date: Apr. 2000
Revision 0.60