SPRZ575 March   2024 AM67 , AM67A , TDA4AEN-Q1 , TDA4VEN-Q1

 

  1.   1
  2. 1Modules Affected
  3. 2Nomenclature, Package Symbolization, and Revision Identification
    1. 2.1 Device and Development-Support Tool Nomenclature
    2. 2.2 Devices Supported
    3. 2.3 Package Symbolization and Revision Identification
  4. 3Silicon Revision 1.0 Usage Notes and Advisories
    1. 3.1 Silicon Revision 1.0 Usage Notes
      1.      i2134
    2. 3.2 Silicon Revision 1.0 Advisories
      1.      i2049
      2.      i2062
      3.      i2097
      4.      i2120
      5.      i2137
      6.      i2189
      7.      i2190
      8.      i2196
      9.      i2199
      10.      i2208
      11.      i2242
      12.      i2243
      13.      i2249
      14.      i2253
      15.      i2278
      16.      i2279
      17.      i2310
      18.      i2311
      19.      i2312
      20.      i2326
      21.      i2351
      22.      i2362
      23.      i2366
      24.      i2372
      25.      i2383
      26.      i2399
      27.      i2401
      28.      i2407
      29.      i2409
      30.      i2410
  5.   Trademarks
  6. 4Revision 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.