DISK DRIVE OPERATION

t0

ADDR valid (See note 1)

t1 t2

DIOR-/DIOW-

WRITE

DD(15:0) (See note 2)

READ

DD(15:0) (See note 2)

IORDY (See note 3,3-1)

 

tA

IORDY

 

(See note 3,3-2)

tC

IORDY

 

(See note 3,3-3)

 

t9

t2i

t3t4

t5t6

t6z

tRD

tBtC

NOTES −

1Device address consists of signals CS0-, CS1- and DA(2:0)

2Data consists of DD(15:0).

3The 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 tA from the assertion of DIOR- or DIOW-. The 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 tA, but causes IORDY to be asserted before tA. IORDY is released prior to negation and may be asserted for no more than 5 ns before release: no wait generated.

3-3 Device negates IORDY before tA. IORDY is released prior to negation and may be asserted for no 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 tRD before asserting IORDY.

4DMACK – shall be negated during a PIO data transfer.

Figure 6-2PIO data transfer to/from device

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Samsung spinpoint v40, 3.5 hard disk drives manual Addr valid See note T1 t2