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S26HL-T/S26HS-T SEMPER™ NOR flash: Switching the mode between HYPERBUS™ and legacy SPI - KBA233740

Chelladurai
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S26HL-T/S26HS-T SEMPER™ NOR flash: Switching the mode between HYPERBUS™ and legacy SPI - KBA233740

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S26HL-T and S26HS-T series SEMPER™ NOR flash devices with HYPERBUS™ interface can support legacy SPI (x1) mode and HYERPBUS™ (x8) mode. The chip ordering part numbers (OPN) of these devices differentiate the factory default work mode as ether legacy SPI (x1) mode or HYPERBUS™ (x8) mode. The two modes can be switched from one to the other as necessary. It requires some configurations and special notices on both host controller and flash side.

Note that the SPI field and HYPERBUS™ field register cannot be accessed in the other mode.

Switch from legacy SPI (x1) mode to HYPERBUS™ (x8) mode:

  1. The host controller in legacy SPI (x1) mode communicates with the flash through the legacy SPI (1S-1S-1S) protocol to access and set CFR3V/N[1] = 1b.
  2. The host controller switches the work mode from legacy SPI to HYPERBUS™. The host controller is now in HYPERBUS™ (x8) mode.
  3. Now, the host controller can communicate with the flash in HYPERBUS™ (x8) protocol. Depending on whether the register write was to the volatile or non-volatile register, the following will happen:
    1. If CFR3V[1] = 1b, the flash will revert to legacy SPI (x1) mode after POR/reset.
    2. If CFR3N [1] = 1b, the flash will keep HYPERBUS™ (x8) mode for further boots.

Switch from legacy SPI (x1) mode to HYPERBUS™ (x8) mode.PNG

Switch from HYPERBUS™ (x8) mode to legacy SPI (x1) mode:

  1. The host controller in HYPERBUS™ (x8) mode communicates with the flash through the HYPERBUS™ (x8) protocol and send ENSPIM_3_0 transaction.
  2. The host controller switches the work mode from HYPERBUS™ to legacy SPI. The host controller is now in legacy SPI (x1) mode.
  3. Now, the host controller can communicate with the flash in legacy SPI (1S-1S-1S) protocol. To set the chip in legacy SPI (x1) mode by default, access and set the non-volatile version register CFR3N[1] = 0b.

Switch from HYPERBUS (x8) mode to legacy SPI (x1) mode.PNG

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Last update:
‎Aug 29, 2021 11:33 PM
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