I wanted to post a bug warning with the current version of the SDK (2.2) for the LPC54608Xpresso board if you want to use the SD card and external SDRAM simultaneously.
Per the Errata:
http://www.nxp.com/docs/en/errata/ES_LPC546XX.pdf
Section 3.7 States that SDIO data line D[4] - D[7] need to configured on the mux for proper 4-bit operation. The errata suggests using unbonded IO in the 180 pin BGA package.
The MCU Xpresso SDK (Version 2.2) uses pins that are shared with the EMC interface. If you have the SDRAM enabled and the pin mux setup for EMC, you will get errors when using any of the SD card drivers in the SDK.
The pin mux settings causing the problem are P1_28,P1_29 and P1_30 (EMC_D12,EMC_D13,EMC_D14)
The pin mux settings must be changed to used the unbonded IO as described in the errata:
1. Enable the SD_D[4] function and on-chip pull-up resistor (via IOCON) on pin PIO4_29.
2. Enable the SD_D[5] function and on-chip pull-up resistor (via IOCON) on pin PIO4_30.
3. Enable the SD_D[6] function and on-chip pull-up resistor (via IOCON) on pin PIO4_31.
4. Enable the SD_D[7] function and on-chip pull-up resistor (via IOCON) on pin PIO5_0.
