How to enable SDR104 mode with full speed on STM32MP15x platform?

[desteibe]

Dear Community,

we are bringing up our own HW platform based on the STM32MP151A MPU. The use-case currently is that we obtain data permanently over several hours and store it on a sd card at a speed of max. 15MByte/sec. After the data acquisition we want to read out the data from the system as fast as possible without removal of the SD Card (not possible) via Gigabit Ethernet.

The problem is that we just learned in the latest errata sheet that SDR104 mode should be avoided (Errata Link 2.3.19) . This would mean that we need to fall back to SDR50/DDR50 with 50MByte/sec max which would mean that the effective read out speed is theoretically limited by the SD Card interface at around 400Mbit at SDR50 instead of 832Mbit at SDR104.

Is there any way to enable SDR104 mode (for 104MByte/sec datarate) or is there aplan to e.g. update the silicon to solve this issue?

BR,

Bernhard

[PatrickF]

Hi,

unfortunately, the SDR104 is not available and there is no plan to correct the silicon.

Note that even if it was bug free, the IOs and the external circuitry (level translator) would have been limiting the clock speed to a realistic value around 130 MHz (which were resulting in max 520 MBit/s).

As you have seen, on STM32MP15 series, you are limited to 50 MBytes/s raw bandwidth when using SD-Card.

Regards.