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DISK DRIVE OPERATION
ADDR valid
(See note 1)
DIOR-/DIOW-
WRITE
DD(15:0)
(See note 2)
READ
DD(15:0)
(See note 2)
IORDY
(See note 3,3-1)
IORDY
(See note 3,3-2)
IORDY
(See note 3,3-3)
NOTES −
1 Device address consists of signals CS0-, CS1- and DA(2:0)
2 Data consists of DD(15:0).
3 The negation of IORDY by the device is used to extend the PIO cycle. The determination of whether the
cycle is to be extended is made by the host after t
assertion and negation of IORDY are described in the following three cases:
3-1 Device never negates IORDY, devices keeps IORDY released: no wait is generated.
3-2 Device negates IORDY before t
prior to negation and may be asserted for no more than 5 ns before release: no wait generated.
3-3 Device negates IORDY before t
more than 5 ns before release: wait generated. The cycle completes after IORDY is reasserted.
For cycles where a wait is generated and DIOR- is asserted, the device shall place read data on
DD(15:0) for t
4 DMACK – shall be negated during a PIO data transfer.
92
t
0
t
1
t
A
, but causes IORDY to be asserted before t
A
. IORDY is released prior to negation and may be asserted for no
A
before asserting IORDY.
RD
Figure 6-2 PIO data transfer to/from device
t
2
t
t
3
t
5
t
C
t
RD
t
t
B
C
from the assertion of DIOR- or DIOW-. The
A
SpinPoint V40 Product Manual
t
9
t
2i
4
t
6
t
6z
. IORDY is released
A
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