Seagate 6451 Computer Drive User Manual


 
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
TDTI TJ
TH
TF
TL
TE
Figure 10. Multiword DMA timing
Medalist Pro 6450/6451 Product Manual, Rev. B 39