You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
This documentation outlines the sEMMC Soft Peripheral.
11
+
It covers setup, integration, and operational guidelines for using sEMMC through the nrfx driver API, alongside detailed descriptions of limitations and performance considerations.
12
+
13
+
.. note::
14
+
The current version of sEMMC is based on JEDEC Standard No. 84-B51A.
When working with sEMMC, you should be aware of the following limitations.
7
+
8
+
.. contents::
9
+
:local:
10
+
:depth: 2
11
+
12
+
v0.1.0
13
+
******
14
+
15
+
Refer to the following detailed descriptions of current limitations:
16
+
17
+
* sEMMC does not support octal-lane data transmissions.
18
+
* sEMMC does not support dual data rate, and as such no support for HS400.
19
+
* :c:var:`nrf_semmc_config_t.read_delay` can not be equal to or higher than the :c:var:`clkdiv` parameter in :ref:`semmc_timing`.
20
+
* :c:var:`clkdiv` parameter in :ref:`semmc_timing` must be even.
21
+
* Maximum frequency is limited to 80MHz on nRF54H Series (assuming a maximum device frequency of 320MHz, in HS200 mode) and 32MHz on nRF54L Series devices.
22
+
* A tuning cycle using CMD21 might be needed to set the proper value of :c:var:`nrf_semmc_config_t.read_delay`.
23
+
* Data buffers and response buffers needs to be pointers with a 32-bit aligned address.
24
+
* :c:var:`nrf_emmc_data_t.block_size` needs to be minimum 4 bytes for quad-lane data transmissions.
25
+
* Setting :c:var:`nrf_semmc_config_t.process_response` to ``NRF_EMMC_RESPONSE_PROC_IGNORE`` will only apply to any transaction in the read direction.
26
+
* sEMMC is not able to process response and data at the same time. See for example :ref:`semmc_nrf54H_series_porting_guide_read_response` on how to mitigate this.
27
+
* Any prepared transfer with :c:func:`nrf_semmc_cmd_prepare` will be discarded when using :c:func:`nrf_semmc_disable`.
0 commit comments