Fujitsu MPG3XXXAT manual Terminating an Ultra DMA data out burst

b)Device pausing an Ultra DMA data out burst

1)The device shall not pause an Ultra DMA burst until at least one data word of an Ultra DMA burst has been transferred.

2)The device shall pause an Ultra DMA burst by negating DDMARDY-.

3)The host shall stop generating HSTROBE edges within tRFS of the device negating DDMARDY-.

4)If the device negates DDMARDY- within tSR after the host has generated an HSTROBE edge, then the device shall be prepared to receive zero or one additional data words. If the device negates DDMARDY- greater than tSR after the host has generated an HSTROBE edge, then the device shall be prepared to receive zero, one or two additional data words. The additional data words are a result of cable round trip delay and tRFS timing for the host.

5)The device shall resume an Ultra DMA burst by asserting DDMARDY-.

5.5.4.4Terminating 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 5.6.3.10 and 5.6.3.2 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 tSS 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 tLI 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 tLI 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 tLI 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 tMLI after the host has asserted HSTROBE and STOP and the device has negated DMARQ and DDMARDY-, and no sooner than tDVS 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-.

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