SPRZ457H January   2021  – December 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442

 

  1.   1
  2. 1Usage Notes and Advisories Matrices
    1. 1.1 Devices Supported
  3. 2Silicon Usage Notes and Advisories
    1. 2.1 Silicon Usage Notes
      1.      i2287
      2.      i2351
    2. 2.2 Silicon Advisories
      1.      i2049
      2.      i2062
      3.      i2103
      4.      i2184
      5.      i2189
      6.      i2236
      7.      i2185
      8.      i2196
      9.      i2207
      10.      i2208
      11.      i2228
      12.      i2232
      13.      i2244
      14.      i2245
      15.      i2091
      16.      i2235
      17.      i2303
      18.      i2317
      19.      i2134
      20.      i2257
      21.      i2277
      22.      i2285
      23.      i2310
      24.      i2311
      25.      i2313
      26.      i2328
      27.      i2241
      28.      i2279
      29.      i2307
      30.      i2320
      31.      i2329
      32.      i2331
      33.      i2243
      34.      i2249
      35.      i2256
      36.      i2274
      37.      i2278
      38.      i2306
      39.      i2363
      40.      i2312
      41.      i2371
      42.      i2366
      43.      i2138
      44.      i2253
      45.      i2259
      46.      i2283
      47.      i2305
      48.      i2326
      49.      i2368
      50.      i2383
      51.      i2401
      52.      i2409
  4.   Trademarks
  5.   Revision History

i2351

OSPI: Direct Access Controller (DAC) does not support Continuous Read mode with NAND Flash

Details:

The OSPI Direct Access Controller (DAC) doesn’t support Continuous Read mode with NAND Flash since the OSPI controller can deassert the CSn signal (by design intent) to the Flash memory between internal DMA bus requests to the OSPI controller.

The issue occurs because “Continuous Read” mode offered by some OSPI/QSPI NAND Flash memories requires the Chip Select input to remain asserted for an entire burst transaction.

The SoC internal DMA controllers and other initiators are limited to 1023 B or smaller transactions, and arbitration/queuing can happen both inside of the various DMA controllers or in the interconnect between any DMA controller and the OSPI peripheral. This results in delays in bus requests to the OSPI controller that result in the external CSn signal being deasserted.

NOR Flash memories are not affected by CSn de-assertion and Continuous Read mode works as expected.

Workaround(s):

Software can use page/buffered read modes to access NAND flash.