Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

5.3.6.4.5.7. Support of TLC (pSLC Mode) Devices

The controller supports TLC devices in the pSLC mode only for ONFI devices:

  • Methods available in ONFI devices
  • Method available in toggle devices

TLC devices in pSLC mode do not have a continuous row address space because the number of pages per block is lower. Because of this, between the page and block address the zero padding is added on the unused bits. To address this in the NAND Flash controller, the PPB field in the nf_dev_layout (0x0424) register needs to be configured with the number of pages per block and the blk_addr_idx in the nf_dev_layout (0x0424) register needs to be configured to point to the bit index inside the row address where block address starts.

To support ONFI device, you can use one of the following three methods:

  • Use the SET FEATURE command to switch device to the pSLC mode. To switch device from TLC to pSLC mode host need to set bit per cell feature value placed under the 0x91 address.
  • Use dedicated pair of commands: 0xDA — to enable the pSLC mode, 0xDF — to disable the pSLC. Switching sequence is not automatic. The preferred solution is to use the SET FEATURE command.
  • Use the 0x3B prefix command in front of selected sequences.