Part II: PCM-959/phyCORE-OMAP44xx Carrier Board
phyCORE-OMAP44xx
136
©
PHYTEC Messtechnik GmbH
2012
L-760e_1
The phyCORE Carrier Board provides two standard SDHC card slots at X10 and X11 for connection to SD/MMC
interface cards. It allows easy and convenient connection to peripheral devices like SD- and MMC cards.
Power to the SD interface is supplied by sticking the appropriate card into the SD/MMC slot.
SD/MMC card slot 2 (X10) connects to the OMAP44xx's SD / MMC Card interface SDMMC5. The signals are shifted
from VCC_1V8_IO (1.8 V) at the phyCORE Connector to VCC_SDMMC5 by level shifter U37. Jumper J12 allows to
change the voltage level of the supply voltage (VCC_SDMMC5). The default level is 3.3 V (VCC_3V3) (J12 at
position 1+2). Closing jumper J12 at 2+3 results in a supply voltage of 1.8 V (VCC_1V8). Removing the level
shifter and mounting RN1, R157 and R155 connects the SD / MMC Card interface SDMMC5 of the phyCORE-
OMAP44xx directly to SD/MMC card slot 2 (X10).
SD/MMC card slot 1 (X11) connects to the OMAP44xx's SD / MMC Card interface SDMMC1. The card slot is
connected directly to the phyCORE-OMAP44xx. Howvere, the power supply for SD/MMC card slot 1(X11) is
variable adjustable by the PMIC of the phyCORE-OMAP44xx. For more information please see
Note:
The SDMMC5 Bus on connector X10 doesn't have the full supported MMC bus speed of the phyCORE-OMAP44xx.
The reason is the level-shifter U37, which limits the speed on 60 Mbps by 3V3 MMC- \ SD cards and 40 Mbps by
1V8 MMC- \ SD cards.