Fujitsu MHV2060AS, MHV2080AS, MHV2040AS manual Ultra DMA Feature Set

Models: MHV2060AS MHV2080AS MHV2040AS

1 280
Download 280 pages 57.54 Kb
Page 217
Image 217

5.5 Ultra DMA Feature Set

6)The host shall drive DD (15:0) no sooner than tZAH after the device has negated DMARQ. For this step, the host may first drive DD (15:0) with the result of its CRC calculation (see 5.5.5):

7)If DSTROBE is negated, the device shall assert DSTROBE within tLI after the host has asserted STOP. No data shall be transferred during this assertion. The host shall ignore this transition on DSTROBE. DSTROBE shall remain asserted until the Ultra DMA burst is terminated.

8)If the host has not placed the result of its CRC calculation on DD (15:0) since first driving DD (15:0) during (6), the host shall place the result of its CRC calculation on DD (15:0) (see 5.5.5).

9)The host shall negate DMACK- no sooner than tMLI after the device has asserted DSTROBE and negated DMARQ and the host has asserted

STOP and negated HDMARDY-, and no sooner than tDVS after the host places the result of its CRC calculation on DD (15:0).

10)The device shall latch the host's CRC data from DD (15:0) on the negating edge of DMACK-.

11)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).

12)The device shall release DSTROBE within tIORDYZ after the host negates DMACK-.

13)The host shall not negate STOP no assert HDMARDY- until at least tACK after negating DMACK-.

14)The host shall not assert DIOR-, CS0-, CS1-, DA2, DA1, or DA0 until at least tACK after negating DMACK.

b)Host terminating an Ultra DMA data in burst

The following steps shall occur in the order they are listed unless otherwise specifically allowed (see 5.6.3.6 and 5.6.3.2 for specific timing requirements):

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

2)The host shall initiate Ultra DMA burst termination by negating HDMARDY-. The host shall continue to negate HDMARDY- until the Ultra DMA burst is terminated.

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

C141-E221

5-141

Page 217
Image 217
Fujitsu MHV2060AS, MHV2080AS, MHV2040AS manual Ultra DMA Feature Set