======================================================================
=                                UDMA                                =
======================================================================

                            Introduction
======================================================================
The Ultra DMA (Ultra Direct Memory Access, UDMA) modes are the fastest
methods used to transfer data through the ATA hard disk interface,
usually between a computer and an ATA device. UDMA succeeded
Single/Multiword DMA as the interface of choice between ATA devices
and the computer. There are eight different UDMA modes, ranging from 0
to 6 for ATA (0 to 7 for CompactFlash), each with its own timing.

Modes faster than UDMA mode 2 require an 80-conductor cable to reduce
data settling times, lower impedance and reduce crosstalk.

Transfer modes
Mode || Number || Also called || Maximum transfer rate (MB/s) ||
Minimum cycle time || Defining standard
rowspan=8 | Ultra DMA   0                16.7    120 ns          ATA-4
1                25.0    80 ns   ATA-4
2       Ultra ATA/33     33.3    60 ns   ATA-4
3                44.4    45 ns   ATA-5
4       Ultra ATA/66     66.7    30 ns   ATA-5
5       Ultra ATA/100    100     20 ns   ATA-6
6       Ultra ATA/133    133     15 ns   ATA-7
7                167     12 ns   CompactFlash 6.0


                              See also
======================================================================
* PIO--The first interface type used between devices (mainly hard
disks) and the computer.
* Parallel ATA
* Serial ATA


License
=========
All content on Gopherpedia comes from Wikipedia, and is licensed under CC-BY-SA
License URL: http://creativecommons.org/licenses/by-sa/3.0/
Original Article: http://en.wikipedia.org/wiki/UDMA

You are viewing proxied material from gopherpedia.com. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.