Ultra Dma Timings; Initiating Read Dma - Hitachi 7K250 - Deskstar - Hard Drive Specifications

7.8 Ultra DMA timings

The Ultra DMA timings meet Mode 0, 1, 2, and 4 of the Ultra DMA Protocol.

7.8.1 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
Figure 4: Ultra DMA cycle timings (Initiating Read)
Deskstar 7K250 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
52
tCYC
tDH
xxx
RD Data
MODE 4
MAX MIN MAX MIN
– 0 –
– 20 – 20
55 20 55 20
– 0 –
130 0 120
– 25 – 17
– 57 – 38
10 – 10
– 0 –
– 5 – 4.8
– 5 – 4.8
– 6.7 – 25
MODE 5
MAX
0 –
–
50
0 –
– 90
–
–
10
0 –
–
–
–