User Manual

EMMY-W1 series - User Manual
UBX-16015271 - R03 Product Information Interfaces
Page 10 of 46
2 Interfaces
2.1 Operation mode configuration
EMMY-W1 series module uses the GPIO_3 and GPIO_2 pins as host interface configuration input to set the
desired operation mode following a reset. The definitions of these pins are changed to their usual functions after
reset. When you need to configure the pins for a certain module operation mode, you need to provide a 100 kΩ
pull down resistor to the ground. No external circuitry is required to set a configuration pin to high logical level.
External reset is not needed for proper operation due to internal power-up reset logic though it can be used by
the host controller through the PDn pin (active low) in case of an abnormal module behavior.
After reset, GPIO_3 and GPIO_2 pins can be used as open drain outputs (depending on firmware/driver version)
for Bluetooth and Wi-Fi activity LED indicators, but simultaneous usage of an LED connected to 3.3 V power line
and a pull-down resistor is not allowed (LED acts as a strong pull-up circuitry). Do not connect LED if you need
the pull-down resistors.
Depending on the firmware or driver used, you can use either one or both host interface operation modes:
GPIO_3
GPIO_2
Wi-Fi
Bluetooth/NFC
Number of SDIO functions
0
0
SDIO
UART
1 (Wi-Fi)
0
1
SDIO
SDIO
3 (Wi-Fi, Bluetooth and NFC)
1
0
SDIO
UART
1 (Wi-Fi)
1
1
SDIO
SDIO
3 (Wi-Fi, Bluetooth and NFC)
6
Table 3: Module configuration
2.2 SDIO interface
EMMY-W1 series modules support an SDIO device interface that conforms to the industry standard SDIO 3.0
Full-Speed specification (4-bit SDIO up to 208 MHz) and allows a host controller using the SDIO bus protocol to
access the Wi-Fi and Bluetooth functions. The interface supports 4-bit SDIO transfer mode at the full clock range
of 0 to 208 MHz.
2.2.1 Default speed and High speed modes
Figure 3: SDIO protocol timing diagram- Default speed mode (3.3 V)
6
Default configuration. It is possible to use connected LEDs to both the pins.