Device
Device
TWL5030
TWL5030
SD/MMC
Port 1
SD/MMC
Port 2
VDDS
VDDS
VDDS_SDMMC1
VMMC1_LDO
VMMC2_LDO
VIO
SDMMC1
SDMMC2
VIO
VIO VCORE
init-032
Public Version
Device Initialization by ROM Code
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26.4.7.6.1.1 Booting From MMC/SD/eMMC/eSD Memory in Case TWL5030 is Implemented
Before performing a memory access, the ROM code tries to detect the presence of a TWL5030 power
management device on the I
2
C bus. If one is detected, the ROM code assumes that the connections
shown in
are present.
Figure 26-25. TWL5030 Connectivity Constraints to Support MMC/SD/eMMC/eSD Booting on SD/MMC
Port 1 and SD/MMC Port 2
The ROM code configures the TWL5030 through I
2
C to set the following:
•
VMMC1_LDO is set to 3.0 V when booting from MMC port 1 is requested from the sys-boot pins.
•
VMMC2_LDO is set to 3.0 V when a booting from MMC port 2 is requested from the sys-boot pins.
Users must furnish VIO = 1.8 V to the SD/MMC memory, respecting the timing sequence imposed by
the memory.
26.4.7.6.1.2 Booting From eMMC/eSD Memory From SD/MMC Port 1 When TWL5030 is Implemented
ROM code can boot from the embedded multimedia card/embedded SD card (eMMC/eSD) on port 1.
Most of these memories require two power supplies: One power supply is required for the I/O interface
(CMD, CLK, DAT[3:0]), and the other is required for the memory core. The VIO voltage is typically 1.8 V,
and the VCORE voltage is 3.0 V.
For eMMC/eSD booting with two power supplies, the implementation shown in
is required.
3560
Initialization
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated