SiRFatlasV
Hardware Design Guide
January, 2010
SiRF Design Guide
– Proprietary and Confidential
10
Figure 4: ADC Power Supply and Reference Decoupling
SD/MMC
Add an external pull-up resistor to all data and command signals when using an SD/MMC card or an
iNAND/moviNAND card.
Use SD0 but not SD2 as the boot media.
For MMC/ moviNAND, the pull-up resistor should be:
50 kOhm ~ 100 kOhm for the DATA net
4.7 kOhm ~ 100 kOhm for the CMD net
For SD/iNAND, the pull-up resistors to all data and command signals should be 10 kOhm ~ 100 kOhm.
Add a quick discharging circuit by pulling the SD0's power low to GND with a 1 kOhm resistor when SD0
is in power-down state (see R307 to Q303 in Figure 5
.) The reason for doing this is:
The iNAND may not reboot normally if it did not discharge after power-off.
