6.10 Ultra DMA timings
The Ultra DMA timings meet Mode 0, 1, 2, and 4 of the Ultra DMA Protocol.
6.10.1 Initiating Read DMA
DMARQ
DMACK-
STOP
HDMARDY-
DSTROBE
DD(15:0)
PARAMETER
DESCRIPTION
(all values in ns)
tUI
Unlimited interlock time
tACK
Setup time for DMACK-
tENV
Envelope time
Minimum time before driv-
tZIORDY
ing IORDY
tFS
First DSTROBE time
tCYC
Cycle time
t2CYC
Two cycle time
Maximum time allowed for
tAZ
output drivers to release
tZAD
Drivers to assert
tDS
Data setup time at host
tDH
Data hold time at host
Time from data ouput
tDZFS
released-to-driving until the
first transition of critical timing
tUI
tACK
tENV
tACK
tENV
tZIORDY
tAZ
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Host drives DD
MODE 0
MODE 1
MIN
MAX
MIN
0
–
0
20
–
20
20
70
20
0
–
0
0
230
0
112
–
73
230
–
154
–
10
–
0
–
0
15
–
10
5
–
5
70
–
48
Deskstar T7K250 Hard Disk Drive Specification
t2CYC
tFS
tCYC
tDS
tZAD
xxx
xxxx
RD Data
RD Data
Device drives DD
MODE 2
MODE 3
MAX
MIN
MAX
MIN
–
0
0
0
–
20
–
20
70
20
70
20
–
0
–
0
200
0
170
0
–
54
–
39
–
115
–
86
10
–
10
–
–
0
–
0
–
7
–
7
–
5
–
5
–
31
–
20
35
tCYC
tDH
xxx
RD Data
MODE 4
MAX
MIN
MAX
MIN
–
0
–
–
20
–
55
20
55
–
0
–
130
0
120
–
25
–
–
57
–
10
–
10
–
0
–
–
5
–
4.8
–
5
–
4.8
–
6.7
–
MODE 5
MAX
0
–
20
–
20
50
0
–
–
90
17
–
–
38
10
0
–
–
–
25
–