Specification
NET2272 USB Peripheral Controller
______________________________________________________________________________
NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490
FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
96
10.4.9 Local Bus DMA Read; Slow Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
DESCRIPTION
MIN
TYP
MAX
UNIT
T20
Read enable true to DREQ false (2)
25
50
60
ns
T21
Read enable false to DREQ true
16
50
68
ns
T22
Data access time from read enable (1)
16
ns
T23
Data tri-state time from end of read enable
2
12
ns
T24
Width of EOT# pulse (3)
10
ns
T25
DREQ false to DREQ true
15
25
ns
(1) 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#.
(2) The minimum value is only guaranteed if the DMA Request Enable bit in the DMAREQ register is set.
(3) EOT#, DACK#, and optionally, IOR# or DMARD# must all be true for at least T24 for proper recognition of the
EOT# pulse.
(4) 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)
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