User Manual

Smart Machine Smart Decision
SIM7100_Hardware_Design_V1.02 2015-06-16
3.6.2 PCM Application Guide
The following figure shows the external codec reference design.
Figure 26: Audio Codec Reference Circuit
Note: SIM7100 can transmit PCM data by the USB port besides the PCM interface. For more
details please refer to documents [1] and [23].
3.7 SD Interface
SIM7100 provides a 4-bit SD/MMC interface with clock rate up to 52 MHz. The voltage of
MMC/SD interface is 2.95V with SD/MMC memory cards up to 2 TB, which is compatible with
SDIO Card Specification (version 3.0), Secure Digital (Physical Layer Specification, version 3.0)
and Multimedia Card Host Specification MMC (version 4.4).
Table 16: MMC/SD Electronic characteristic (SD_DATA0-SD_DATA3， SD_CLK and
SD_CMD) *
Symbol Parameter
Min. Typ. Max. Unit
VDD_EXT
LDO power output
voltage**
2.75 2.95 3.05 V
V
IH
High-level input voltage 0.65·VDD_EXT - VDD_EXT+0.3 V
V
IL
Low-level input voltage -0.3 0 0.25·VDD_EXT V
V
OH
High-level output voltage
VDD_EXT-0.4 2.95 VDD_EXT
V
V
OL
Low-level output voltage 0 0 0.45 V
Note:
*Be different from SD_DATA0-SD_DATA3 ， SD_CLK and SD_CMD ， SD1_DET is 1.8V
operation voltage.