VIM3 and sdcard reader in sdr-104 / UHS-I mode


according to the datasheet

The sdcard reader is capable of sdr-104 / UHS-I mode:

  • SDSC/SDHC/SDXC card and SDIO interface with 1-bit and 4-bit data bus width supporting specversion 2.x/3.x/4.x DS/HS modes up to UHS-I SDR104

But actually it is only running in high speed mode, not ultra speed mode (at least in coreelec):


sd: new high speed SDXC card at address 0007

cat /sys/kernel/debug/sd/ios:

clock: 50000000 Hz

actual clock: 50000000 Hz

vdd: 21 (3.3 ~ 3.4 V)

bus mode: 2 (push-pull)

chip select: 0 (don't care)

power mode: 2 (on)

bus width: 2 (4 bits)

timing spec: 2 (sd high-speed)

signal voltage: 0 (3.30 V)

driver type: 0 (driver type B)

This leads to only a write/read speed of about 20MB/s also for UHS-I capable sdcards.

Would it be possible, to support sdr-104 / UHS-I mode in coreelec?

1 Like

Hello! I gave an example here how to implement this in the best way!

Same on Ubuntu, R/W speed is around 20MB/s, as advertised on the vim3 product page