Data Sheet

ManualsBrandsTexas Instruments ManualsElectronicsDry erase whiteboard with digital imaging capacity

WL1801MOD,

WL1805MO

WL1831MO

WL1835MOD

SWRS152M – JULY 2013 – REVISED OCTOBER 2017

www.ti.com

Specifications

Submit Documentation

Feedback

Product Folder Links: WL1801MOD WL1805MOD WL1831MOD

WL1835MOD

5.19.7 HCI UART Shared-Transport Layers for All Functional Blocks (Except WLAN)

The device includes a UART module dedicated to the Bluetooth shared-transport, host controller interface

(HCI) transport layer. The HCI transports commands, events, and ACL between the Bluetooth device and

its host using HCI data packets ack as a shared transport for all functional blocks except WLAN. Table 5-3

lists the transport mechanism for WLAN and bluetooth audio.

Table 5-3. Transport

Mechanism

WLAN SHARED HCI FOR ALL FUNCTIONAL BLOCKS EXCEPT WLAN BLUETOOTH VOICE-AUDIO

WLAN HS SDIO Over UART Bluetooth PCM

The HCI UART supports most baud rates (including all PC rates) for all fast-clock frequencies up to a

maximum of 4 Mbps. After power up, the baud rate is set for 115.2 Kbps, regardless of the fast-clock

frequency. The baud rate can then be changed using a VS command. The device responds with a

Command Complete Event (still at 115.2 Kbps), after which the baud rate change occurs.

HCI hardware includes the following features:

• Receiver detection of break, idle, framing, FIFO overflow, and parity error conditions

• Receiver-transmitter underflow detection

• CTS, RTS hardware flow control

• 4 wire (H4)

Table 5-4 lists the UART default settings.

Table 5-4. UART Default

Setting

PARAMETER

VALUE

Bit rate 115.2

Kbps

Data length 8

bits

Stop-bit 1

Parity None

5.19.7.1 UART 4-Wire Interface – H4

The interface includes four signals:

• TXD

• RXD

• CTS

• RTS

Flow control between the host and the device is byte-wise by hardware.

When the UART RX buffer of the device passes the flow-control threshold, the buffer sets the UART_RTS

signal high to stop transmission from the host. When the UART_CTS signal is set high, the device stops

transmitting on the interface. If HCI_CTS is set high in the middle of transmitting a byte, the device

finishes transmitting the byte and stops the transmission.