Fujitsu MHV2120BH, MHV2100BH, MHV2080BH manual DMA data-out command protocol, Write DMA EXT FUA EXT

Interface

5.4.5 DMA data-out command protocol

The DMA data-out command is the following command:

•WRITE DMA (EXT) (FUA EXT)

The DMA mechanism transfers data of more than one block from the host to the device. The completion of the command is reported by an interruption.

An outline of this protocol is as follows:

1)The device receives the DMA data-out command with the RegHD FIS.

2)If an error remaining in the device prevents command execution, the device sends the RegDH FIS with 1 set in the I bit.

3)When the device is ready to receive data, it sends the DMA Active FIS to the host.

4)The device receives the Data FIS from the host.

5)When all data has been transferred, the device sends the RegDH FIS (with 1 set in the I bit) to complete execution of the command. If any data remains to be received by the device, this protocol is repeated starting from step 3). (The maximum data size is 8 KB.)

RegHD

Host

DMA Active

Device

DATA

RegDH

Figure 5.17 DMA data-out command protocol

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