Mirek Kwasniak (mirek@zind.ikem.pwr.wroc.pl)
Tue, 3 Aug 1999 19:43:49 +0200
On Sat, Jul 31, 1999 at 12:01:11PM +0200, Uwe Klein wrote:
> hi,
> I got about 1.2 MByte in ECP Fifo/DMA ( 8Bit BusInteface ) mode
> outbound. This speed seems to be ISA Bus bound.
>
> While the FIFO is filled/emptied you will get a transfer every 500us
> which would suggest that the max ECP speed is about 2MByte.
>
Hi,
Information
Brief specifications for comparing the ECP parallel port (on late
model Toshiba computers) and EPP parallel port hardware.
EPP - Enhanced Parallel Port
* 1-3 MB/sec
* Asynchronous, interlocked, bi-directional communication - Half
Duplex Operation
* Targeted at register oriented type devices:
* Network Adapters
* Tape backup
* CD-ROM
* Master/slave architecture
* Peripheral is polled for data
* Supports peripheral interrupt
* Supports two cycle types:
* Address/command
* Data
* Symmetric Read/Write cycles
* Hardware assisted handshaking/data transfer
* Limited by I/O cycle capabilities of the implementation
ECP - Extended Capability Port
* 5 MB/Sec
* Asynchronous, interlocked, bi-directional communication - Half
Duplex Operation
* Targeted at block oriented type devices:
* Printers
* Scanners
* May have hardware support for RLE compression or decompression
(optional)
* Supports 2 cycle types:
* Channel Address
* Data
* Peer to 'Peerish'
* Peripheral may request the reverse channel, but the host controls
the data transfer
* Hardware assisted handshaking/data transfer
* Implementations include DMA as well as programmed I/O PC interface
* Data transfer rate limited by the DMA or I/O cycle capabilities of
the implementation
Mirek
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This archive was generated by hypermail 2.0b3 on Tue 03 Aug 1999 - 13:52:13 EDT