Filter
Top Products
5.5 Ultra DMA Feature Set
C141-E050-02EN 5-87
5.5.4.4 Terminating an Ultra DMA data out burst
a) Host terminating an Ultra DMA data out burst
The following stops shall occur in the order they are listed unless otherwise
specifically allowed (see 5.6.4.10 and 5.6.4.2 for specific timing
requirements):
1) The host shall initiate termination of an Ultra DMA burst by not
generating HSTROBE edges.
2) The host shall assert STOP no sooner than t
SS
after it last generated an
HSTROBE edge. The host shall not negate STOP again until after the
Ultra DMA burst is terminated.
3) The device shall negate DMARQ within t
LI
after the host asserts STOP.
The device shall not assert DMARQ again until after the Ultra DMA
burst is terminated.
4) The device shall negate DDMARDY- with t
LI
after the host has negated
STOP. The device shall not assert DDMARDY- again until after the
Ultra DMA burst termination is complete.
5) If HSTROBE is negated, the host shall assert HSTROBE with t
LI
after
the device has negated DMARQ. No data shall be transferred during this
assertion. The device shall ignore this transition on HSTROBE.
HSTROBE shall remain asserted until the Ultra DMA burst is
terminated.
6) The host shall place the result of its CRC calculation on DD (15:0) (see
5.5.5)
7) The host shall negate DMACK- no sooner than t
MLI
after the host has
asserted HSTROBE and STOP and the device has negated DMARQ and
DDMARDY-, and no sooner than t
DVS
after placing the result of its CRC
calculation on DD (15:0).
8) The device shall latch the host's CRC data from DD (15:0) on the
negating edge of DMACK-.
9) The device shall compare the CRC data received from the host with the
results of its own CRC calculation. If a miscompare error occurs during
one or more Ultra DMA bursts for any one command, at the end of the
command, the device shall report the first error that occurred (see 5.5.5).
10) The device shall release DDMARDY- within t
IORDYZ
after the host has
negated DMACK-.
11) The host shall neither negate STOP nor negate HSTROBE until at least
t
ACK
after negating DMACK-.
12) The host shall not assert DIOW-, CS0-, CS1-, DA2, DA1, or DA0 until
at least t
ACK
after negating DMACK.