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Visible to Intel only — GUID: sfo1410068482614
Ixiasoft
14.4.9.2. Burst DMA Command
You can initiate a DMA transfer by sending a command to the NAND flash controller as a burst transaction of four 16‑bit accesses. This form of DMA command might be useful for initiating DMA transfers from custom IP in the FPGA fabric. Most processor cores cannot use this form of DMA command, because they cannot control the width of the burst.
When DMA is enabled, the NAND flash controller recognizes the MAP10 pipeline DMA command as an INCR4 command, in the format shown in the following table. The address decoding for MAP10 pipeline DMA command remains the same, as shown in "MAP10 Command Format".
MAP10 commands in INCR4 format are written to the Data register at offset 0x10 in nanddata, the same as MAP10 commands in multitransaction format (described in the "Multi-Transaction DMA Command").
Data Beat | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Beat 0 | 0x2 | 0x0: read. 0x1: write. | <PP>=number of pages | |||||||||||||
Beat 130 | Memory address high | |||||||||||||||
Beat 230 | Memory address low | |||||||||||||||
Beat 3 | 0x0 | INT31 | Burst length | |||||||||||||
Note: INT controls the value of the dma_cmd_comp bit of the intr_status0 register in the status group at the end of the DMA transfer. INT can take on one of the following values: 0—Do not interrupt host. The dma_cmd_comp bit is set to 0. 1—Interrupt host. The dma_cmd_comp p bit is set to 1. |
You can optionally send the 16‑bit fields in the above table to the NAND flash controller as four separate bursts of length 1 in sequential order. Intel recommends this method.
If you want the NAND flash controller DMA to perform cacheable accesses, you must configure the cache bits by writing the l3master register in the nandgrp group in the system manager. The NAND flash controller DMA must be idle before you use the system manager to modify its cache capabilities.