AnsweredAssumed Answered

SD card initialization

Question asked by matthias on Jun 11, 2015
Latest reply on Jun 23, 2015 by Iva Susnova



I am trying to get an SD card working. I am using KDS3.0/KSDK1.2.0 with Processor Expert and MQX. The hardware uses a 1bit bus and it looks like the maximum clock frequency should be below 10 MHz.
I tried to use SDCARD_DRV_Init() to initialize the card without success. When I look at the code I see that in SDCARD_DRV_InitSd() the clock is hard coded to 25 MHz and for some reason my host thinks it supports a 4 bit bus (see picture below). The SD card component uses the fsl_sdhc component and in KSDK1.1.0 it was possible to configure the bus witdh but this PExpert item has disappeared in KSDK1.2.0. But anyway, even if I auto initialise fsl_sdhc in Cpu.c it seems that the configurations I make there are completely ignored and overwritten when SDCARD_DRV_Init() is called. For example, I have set the bus clock to 2 MHz but as said the clock is hard coded to 25 MHz in SDCARD_DRV_InitSd().

Can anyone give some hints how to properly configure the SD card driver? The KSDK Reference Manual does not give much useful information here.