UM1865 datasheet(8/132 Pages) STMICROELECTRONICS

8 / 132 page

Overview

UM1865

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DocID027514 Rev 1

Figure 2. Bluetooth LE system with combined host and controller

1.1

BlueNRG-MS ACI architecture

The BlueNRG-MS is implemented using a combined host and controller solution. An

application command interface (ACI) is provided for accessing the BlueNRG-MS host and

controller.

User applications, i.e. programs running in another silicon chip, can send ACI commands to

control the BlueNRG-MS. The ACI commands should be sent over an SPI connection. The

SPI protocol is described in a later section.

The ACI interface also supports HCI commands. If a command is received the ACI will

check whether the command is for the host or for the controller. If the command is a HCI

command, i.e. a command for the controller, the ACI will forward directly the command to

the controller, bypassing it from the host. This implementation has two advantages: (1)

normally the host can control the LL/PHY without using the HCI commands, which improves

performance, and (2) user applications can still test the controller individually or set up some

low-level hardware parameters with the HCI commands, without going through the host.

Figure 3. BlueNRG-MS ACI architecture

UM1865 Datasheet(PDF) 8 Page - STMicroelectronics