PAN1326C Bluetooth Module
2 Overview
Product Specification Rev. 1.0
Page 14
2.6 Interfaces
2.6.1 Host Controller Interface (HCI)
The CC2564C incorporates one UART module dedicated to the host controller interface (HCI)
transport layer. The HCI interface transports commands, events, ACL, and synchronous data
between the Bluetooth device and its host using HCI data packets.
The UART module supports H4 (4-wires) protocol with maximum baud rate of 4 Mbps for all fast
clock frequencies.
After power up the baud rate is set for 115.2 kbps, irrespective of fast clock frequency. The
baud rate can thereafter be changed with a vendor specific command. The CC2564C responds
with a Command Complete Event (still at 115.2 kbps), after which the baud rate change takes
place. HCI hardware includes the following features:
•
Receiver detection of break, idle, framing, FIFO overflow, and parity error conditions
•
Transmitter underflow detection
•
CTS/RTS hardware flow control
The interface includes four signals: TXD, RXD, CTS, and RTS. Flow control between the host
and the CC2564C is byte-wise by hardware.
Flow control is obtained by the following:
When the UART RX buffer of the CC2564C
passes the “flow control” threshold, it will set the
UART_RTS signal high to stop transmission from the host.
When the UART_CTS signal is set high, the CC2564C will stop its transmission on the
interface. In case HCI_CTS is set high in the middle of transmitting a byte, the CC2564C will
finish transmitting the byte and stop the transmission.