Service Guide

Wi-Fi&Bluetooth Module Series
FC908A_Hardware_Design 23 / 49
3.5. WLAN Application Interface
The following figure shows the WLAN application interface connection between FC908A and the host.
Host
FC908A
SDIO
WLAN_ENWLAN_EN
WLAN_WAKEWLAN_WAKE
SDIO
Figure 5: WLAN Application Interface Connection
3.5.1. SDIO Interface
FC908A is used for SDIO 2.0 interface, supports 1-bit mode or 4-bit mode (automatic detection when
SDIO link). SDIO interface definition is as follows:
Table 8: Pin Definition of SDIO Interface
DCR
< 0.2
Ω
Rated current (based on temperature rise）
1.15
A
Pin Name
Pin No.
1-bit Mode
4-bit Mode
SDIO_DATA2
14
NC
SDIO data bit 2
SDIO_DATA3
15
NC
SDIO data bit 3
SDIO_CMD
16
SDIO command
SDIO command
SDIO_CLK
17
SDIO clock
SDIO clock
SDIO_DATA0
18
SDIO data bit 0
SDIO data bit 0
SDIO_DATA1
19
IRQ
SDIO data bit 1