Service Guide

Wi-Fi&Bluetooth Module Series
FC909A_Hardware_Design 27 / 49
3.5. Bluetooth Application Interfaces
The following figure shows the block diagram of Bluetooth application interfaces connection between
FC909A and the host.
PCM
UART
FC909A
UART
PCM
Host
BT_EN
BT_EN
GPIO1
HOST_WAKE_BT
GPIO2
BT_WAKE_HOST
Figure 6: Block Diagram of Bluetooth Application Interfaces Connection
3.5.1. UART
FC909A supports an HCI UART as defined in Bluetooth Core Specification Version 5.1. The UART
supports hardware flow control, and it is used for data transmission with the host. It supports up to 4.0
Mbps baud rates.
Table 13: Pin Definition of UART
Pin Name
Pin No.
I/O
Description
Comment
BT_RTS
41
DO
Bluetooth UART request to send
VDDIO power domain
BT_TXD
42
DO
Bluetooth UART transmit
BT_RXD
43
DI
Bluetooth UART receive
BT_CTS
44
DI
Bluetooth UART clear to send