STLC2416 Datasheet, PDF (23/27 Pages) STMicroelectronics – BLUETOOTH BASEBAND WITH INTEGRATED FLASH

STLC2416
Figure 12. PCM interface timing
t_WCL
PCM_CLK
t_WCH
t_SSC
PCM_SYNC
t_WSH
t_SDC
t_HCD
PCM_A/B in
PCM_B/A out
MSB
MSB-1 MSB-2 MSB-3 MSB-4
t_DCD
MSB
MSB-1 MSB-2 MSB-3 MSB-4
D02TL557
9 HCI UART TRANSPORT LAYER
The UART Transport Layer has been specified by the Bluetooth™ SIG, and allows HCI level communica-
tion between a host controller (STLC2416) and a host (e.g. PC), via a serial line.
The objective of this HCI UART Transport Layer is to make it possible to use the Bluetooth™ HCI over a
serial interface between two UARTs on the same PCB. The HCI UART Transport Layer assumes that the
UART communication is free from line errors.
9.1 UART Settings
The HCI UART Transport Layer uses the following settings for RS232:
– Baud rate:
– Number of data bits:
– Parity bit:
Configurable (Default baud rate: 57.600 kbps)
8
no parity
– Stop bit:
– Flow control:
– Flow-off response time:
1 stop bit
RTS/CTS
3 ms
Flow control with RTS/CTS is used to prevent temporary UART buffer overrun. It should not be used for
flow control of HCI, since HCI has its own flow control mechanisms for HCI commands, HCI events and
HCI data.
If CTS is 1, then the Host/Host Controller is allowed to send.
If CTS is 0, then the Host/Host Controller is not allowed to send.
The flow-off response time defines the maximum time from setting RTS low until the byte flow actually
stops. The signals should be connected in a null-modem fashion; i.e. the local TXD should be connected
to the remote RXD and the local RTS should be connected to the remote CTS and vice versa.
Figure 13. UART Transport Layer
BLUETHOOTH
HOST
BLUETHOOTH HCI
BLUETHOOTH
HOST
CONTROLLER
HCI UART TRANSPORT LAYER
D02TL556
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