
Specification
NET2270 USB Interface Controller
______________________________________________________________________________
NetChip Technology, Inc., 2003
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490
FAX (650) 526-1494
http://www.netchip.com
Rev 3.6, April 17, 2003
88
10.4.9 Local Bus DMA Read
Operating Conditions: VDD: 3.3V ± 5%, TA = 0°C to 70°C, Output Load = 25pF
NAME
DESCRIPTION
MIN
TYP
MAX
UNIT
T20
Read enable true to DREQ false
25
40
56
ns
T21
Read enable false to DREQ true
13
40
72
ns
T22
Data access time from read enable
35
ns
T23
Data tri-state time from end of read enable
0
10
ns
T24
Width of EOT# pulse (see Note 1)
20
ns
T25
DREQ false to DREQ true
13
ns
*For non-split DMA mode, read enable is the occurrence of DACK# and optionally, IOR#.
*For split DMA mode, read enable is the occurrence of DACK# and optionally, DMARD#.
Note 1: EOT#, DACK#, and optionally, IOR# or DMARD# must all be true for at least T24 for proper recognition
of the EOT# pulse.
Note 2: A recovery time of 2 nsec is required between the de-assertion of DMA read enable and the assertion of an
I/O read enable.
T20
T21
T25
T20
T22
T23
T22
T23
T24
D0
D1
0ns
50ns
100ns
150ns
200ns
DREQ
DACK#
IOR# (Optional)
LD[15:0]
EOT# (Optional)