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DISK DRIVE OPERATION
SpinPoint V40 Product Manual
91
Table 6-16 Register transfer to/from device
PIO timing parameters
Mode 0
ns
Mode 1
ns
Mode 2
ns
Mode 3
ns
Mode 4
ns
Note
t
0
Cycle time (min) 600 383 330 180 120 1,4
t
1
Address valid to DIOR-/DIOW- setup (min) 70 50 30 30 25
t
2
DIOR-/DIOW- pulse width 8-bit (min) 290 290 290 80 70 1
t
2i
DIOR-/DIOW- recovery time (min) - - - 70 25 1
t
3
DIOW- data setup (min) 60 45 30 30 20
t
4
DIOW- data hold (min) 30 20 15 10 10
t
5
DIOR- data setup (min) 50 35 20 20 20
t
6
DIOR- data hold (min) 5 5 5 5 5
T
6Z
DIOR- data tristate (max) 30 30 30 30 30 2
t
9
DIOR-/DIOW- to address valid hold (min) 20 15 10 10 10
t
RD
Read Data Valid to IORDY active
(if IORDY initially low after t
A
)
(min) 0 0 0 0 0
t
A
IORDY Setup time 35 35 35 35 35 3
t
B
IORDY Pulse Width (max) 1250 1250 1250 1250 1250
t
C
IORDY assertion to release (max) 5 5 5 5 5
NOTES −
1 t
0
is the minimum total cycle time, t
2
is the minimum command active time, and t
2i
is the minimum command recovery
time or command inactive time. The actual cycle time equals the sum of the actual command active time and the actual
command inactive time. The three timing requirements of t
0
, t
2
, and t
2i
shall be met. The minimum total cycle time
requirements are greater than the sum of t
2
and t
2i
. This means a host implementation may lengthen either or both t
2
or
t
2i
to ensure that t
0
is equal to or greater than the value reported in the devices IDENTIFY DEVICE data. A device
implementation shall support any legal host implementation.
2 This parameter specifies the time from the negation edge of DIOR- to the time that the data bus is no longer driven by
the device (tri-state).
3The delay from the activation of DIOR- or DIOW- until the state of IORDY is first sampled. If IORDY is inactive
then the host shall wait until IORDY is active before the PIO cycle is completed. If the device is not driving IORDY
negated at the t
A
after the activation of DIOR- or DIOW-, then t
5
shall be met and tRD is not applicable. If the device is
driving IORDY negated at the time t
A
after the activation of DIOR- or DIOW-, then t
RD
shall be met and t
5
is not
applicable.
4 Mode shall be selected no faster than the highest mode supported by the slowest device.
6.7.2 PIO data transfers
Figure 6-2 defines the relationships between the interface signals for PIO data transfers. Peripherals
reporting support for PIO mode 3 or 4 shall power up in a PIO mode 0, 1, or 2.
For PIO modes 3 and above, the minimum value of t
0
is specified by word 68 in the IDENTIFY DEVICE
parameter list. Table 6-17 defines the minimum value that shall be placed in word 68.
IORDY shall be supported when PIO modes 3 or 4 are the current mode of operation.
NOTE − Some devices implementing the PACKET Command feature set prior to this
standard power up in PIO mode 3 and enable IORDY as the default.