Figure 8. Programmed I/O Timing With Iordy - Seagate ST3780A Product Manual

32
When using IORDY, the drive operates at programmed timing specifica-
tions, as shown below.
Address valid
IOCS16−
DIOR− or DIOW−
IORDY
Write data valid
Read data valid

Figure 8. Programmed I/O timing with IORDY

Time Description
T0 Cycle time
T1 Address valid until IOCS16– is asserted
Drive address (CS1FX–, CS3FX–,
T2
DA0, DA1 and DA2) valid before DIOR–
or DIOW– setup
T3 IORDY setup time
DIOW– or DIOR– pulse width (8-bit)
T4
DIOW– or DIOR– pulse width (16-bit)
T5 IORDY pulse width
T6 DIOW– data setup
T7 DIOR– data setup
T8 DIOR– data hold
T9 DIOW– data hold
T10 DIOW– or DIOR– to address valid hold
T11 Address valid until IOCS16– is negated
Medalist Family AT Product Manual, Rev. A
T1 T7
T2 T6
T3 T5
T4
T0
120 nsec
T8
T9
T10 T11
Min Max
—
— 30 nsec
25 nsec —
— —
70 nsec —
70 nsec —
1,250
—
nsec
20 nsec —
20 nsec —
5 nsec —
10 nsec —
5 nsec —
— 25 nsec