Seagate Medalist Pro 4520, Руководство по эксплуатации продукта

Страница: 49 / 54

The drives operate at multiword DMA mode 2 timing specifications, as
shown below.
Time Description Min Max
T0 Cycle time 120 nsec —
TD DIOW– or DIOR– pulse width (16-bit) 70 nsec —
TE DIOR– data access — —
TF DIOR– data hold 5 nsec —
TG DIOW– data setup 20 nsec —
TH DIOW– data hold 10 nsec —
TI DMACK– to DIOR– or DIOW– setup 0 nsec —
TJ DIOR– or DIOW– to DMACK– hold 5 nsec —
TK
R
DIOR– negated pulse width 25 nsec —
TK
W
DIOW– negated pulse width 25 nsec —
TL
R
DIOR– to DMARQ delay — 35 nsec
TL
W
DIOW– to DMARQ delay — 25 nsec
DMACK
−
DMARQ
T0
DIOR
−
or DIOW
−
Read data valid
Write data valid
TK
TG
TD TI TJ
TH
TF
TL
TE
Figure 10. Multiword DMA timing
Medalist Pro 9140, 6530 and 4520 Product Manual, Rev. B 41