sEMMC features

This page provides an overview of the functionalities and configurations available for the Soft Peripheral sEMMC for the current state of development. See the following sections for more details.

Command support for EMMC

sEMMC supports the following JEDEC Standard No. 84-B51A command groups:

  • Class 0 - Basic

  • Class 2 - Block read

  • Class 4 - Block write

  • Class 5 - Erase

  • Class 6 - Write protection

  • Class 7 - Lock device

  • Class 11 - Command queuing

HS200 mode support for EMMC

sEMMC supports the HS200 mode for high-speed transfers. This allows sEMMC to operate at frequencies up to 80MHz on the nRF54H20 device.

Note

You need to perform a tuning cycle using CMD21 to find the optimal sampling point for reads. After completing the tuning cycle, set the sampling value in the nrf_semmc_config_t.read_delay variable.

Command support for SDCARD

sEMMC supports the following SD Specifications Part 1 Physical Layer Specification Version 9.10 command groups:

  • Class 0 - Basic

  • Class 2 - Block read

  • Class 4 - Block write

  • Class 5 - Erase

  • Class 6 - Write protection

  • Class 10 - Switch (Only CMD6)

SDR speed modes support for SDCARD

Requires voltage switch from 3.3V to 1.8V, which requires external hardware, theoreticaly it is possible to reach up to SDR50: UHS-I. See sEMMC limitations