FDC37C93XAPM Datasheet, PDF (96/280 Pages) SMSC Corporation – Plug and Play Compatible Ultra I/O™ Controller with Soft Power Management

D7
D6
D5
D4
D3
D2
D1
D0
Note
data
PD7
PD6
PD5
PD4
PD3
PD2
PD1 PD0
ecpAFifo Addr/RLE
Address or RLE field
2
dsr
nBusy
nAck
PError
Select nFault
0
0
0
1
dcr
0
0
Direction ackIntEn SelectIn
nInit
autofd strobe
1
cFifo
Parallel Port Data FIFO
2
ecpDFifo
ECP Data FIFO
2
tFifo
Test FIFO
2
cnfgA
0
0
0
1
0
0
0
0
cnfgB
compress intrValue
Parallel Port IRQ
Parallel Port DMA
ecr
MODE
nErrIntrEn dmaEn serviceIntr full empty
Note 1: These registers are available in all modes.
Note 2: All FIFOs use one common 16 byte FIFO.
Note 3: The ECP Parallel Port Config Reg B reflects the IRQ and DRQ selected by the Configuration
Registers.
It does not do any "protocol" negotiation, rather
ISA IMPLEMENTATION STANDARD
it provides an automatic high burst-bandwidth
channel that supports DMA for ECP in both the
This specification describes the standard ISA forward and reverse directions.
interface to the Extended Capabilities Port
(ECP). All ISA devices supporting ECP must Small FIFOs are employed in both forward and
meet the requirements contained in this section reverse directions to smooth data flow and
or the port will not be supported by Microsoft. improve the maximum bandwidth requirement.
For a description of the ECP Protocol, please The size of the FIFO is 16 bytes deep. The port
refer to the IEEE 1284 Extended Capabilities supports an automatic handshake for the
Port Protocol and ISA Interface Standard, Rev. standard parallel port to improve compatibility
1.14, July 14, 1993. This document is available mode transfer speed.
from Microsoft.
The port also supports run length encoded
Description
(RLE) decompression (required) in hardware.
Compression is accomplished by counting
The port is software and hardware compatible ^{identical bytes and transmitting an RLE byte}
with existing parallel ports so that it may be ^{that indicates how many times the next byte is}
used as a standard LPT port if ECP is not ^{to be repeated. Decompression simply}
required. The port is designed to be simple and ^{intercepts the RLE byte and repeats the}
requires a small number of gates to implement.
following byte the specified number of times.
Hardware support for compression is optional.
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