SoC/ACP Mode (Dual Core)#

In SoC (System-on-Chip) or ACP (Application Co-Processor) mode, the full Bluetooth Low Energy (BLE) stack runs on the Network Processor (NWP), and the on-chip M4 Application Processor communicates with the NWP through the AHB interface and shared memory.

SoC/ACP Mode Architecture#

SoC/ACP Architecture:

Component placement and interfaces:

• Application: Runs on M4 Application Processor

• BLE stack and controller: BLE stack, Link Layer and radio control run on NWP

• Communication: M4 and NWP exchange WiSeConnect API commands, responses, and asynchronous events through AHB interface + shared memory (message buffers)

M4 Responsibilities:

• Application logic

• Message buffer management

• Event handling

NWP Responsibilities:

• Complete BLE stack (GAP, GATT, L2CAP, etc.)

• LE Controller, Link Layer, PHY

• Radio management

SoC/ACP Mode Characteristics#

Advantages:

• Integrated Solution: Single chip solution

• Low Latency: Direct memory access through AHB

• Efficient Communication: Shared memory for high-speed data transfer

• Power Efficiency: Optimized inter-processor communication

Considerations:

• M4 Dependency: Requires M4 to be active

• Memory Sharing: Shared memory management required

• Firmware Coordination: M4 and NWP firmware must be compatible

BLE Operations in SoC/ACP Mode#

API Usage:

• WiSeConnect SDK APIs available directly on M4 Application Processor

• APIs communicate through message buffers through shared memory

• Low-latency communication through AHB interface and shared memory

• No serial interface overhead - direct inter-processor communication

Inter-Processor Communication:

• Message Buffers: Used for command/response and event delivery between M4 and NWP

• AHB Interface: Provides direct memory access for efficient data transfer

• Shared Memory: Enables high-speed bidirectional communication

• SDK handles message buffer management and protocol conversion automatically

Event Handling:

• Events received through message buffers from NWP

• M4 application processes events and responds through SDK APIs

• Efficient event delivery through shared memory with minimal latency

• Event callbacks are registered through the WiSeConnect SDK BLE callback registration APIs; see Callback Registration for the full set (GAP, GATT, SMP, and extended/advertising-extension callbacks)

Configuration:

• BLE configuration through SDK APIs (same APIs as NCP mode)

• System configuration set during initialization (sl_wifi_init() - BLE stack is automatically initialized as part of Wi-Fi stack initialization)

• Runtime configuration through API calls

• No porting required - SDK runs natively on M4

Development Setup: SoC mode development uses Simplicity Studio IDE with WiSeConnect SDK:

• Development Tools: Simplicity Studio 6, GNU ARM Toolchain, WiSeConnect extension

• Hardware: SiWx917 SoC boards (BRD4338A, BRD4342A, BRD4343A, etc.) and kits such as SiW917Y-EK2708A.

• Project Creation: Create projects directly in Simplicity Studio - no porting needed

• Firmware: M4 application firmware and NWP connectivity firmware must be compatible

Reference: See Getting Started with SoC Mode for demo setup and Developing with Radio Boards in SoC Mode for development guidance.

APIs Used in This Section#