Figure 8. Programmed I/O Timing With Iordy - Seagate ST5660A Product Manual

28
When using IORDY, the drive operates at programmed I/O mode 3 timing
specifications, as shown below.
Address valid
IOCS16−
DIOR− or DIOW−
IORDY
Write data valid
Read data valid
T1

Figure 8. Programmed I/O timing with IORDY

Time Description
T0 Cycle time
T1 Address valid until IOCS16– is asserted
Drive address (CS1FX–, CS3FX–, DA0,
T2
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
ST5660A Product Manual, Rev. A
T7
T2 T6
T3 T5
T4
T0
180 nsec
T8
T9
T10 T11
Min Max
—
— 40 nsec
30 nsec —
— —
80 nsec —
80 nsec —
— 1,250 nsec
30 nsec —
20 nsec —
5 nsec —
15 nsec —
10 nsec —
— 30 nsec