SiSDK Platform - CPC Version 4.7.0 (June 16, 2025) - Release Notes#

Simplicity SDK Platform Version 5.2.0

Simplicity SDK Version 2025.6.0

The Co-Processor Communication (CPC) framework enables secure and efficient data exchange between two processors over a shared serial link, acting as a multiplexer to support multiple applications simultaneously. Designed with a Linux host (CPC daemon) as the primary device and an EFR(M) device as the secondary, CPC ensures reliable, in-order, error-free communication over encrypted UART or SPI connections.

Release Summary#

Key Features | API Changes | Bug Fixes | Chip Enablement

Key Features#

  • Added permanent memory allocation initialization for CPC, for Series 3.

  • Improved SPI bitrate configuration to default to 1 MHz when unspecified.

  • Added support for GCC Link Time Optimization (LTO).

API Changes#

  • Introduced sl_cpc_init_permanent_allocations API for permanent memory allocation initialization; sl_cpc_init() continues to handle this for Series 2.

Bug Fixes#

  • Resolved race condition in UART code causing buffer errors.

  • Improved SPI bitrate configuration to make it optional; CPCd.

  • Corrected nonce overflow detection logic in CPC protocol; Protocol bump requried.

  • Fixed link time warnings in GCC LTO compilation for CPC sample apps.

  • Addressed xmodem bootloader (UART) detection causing CPCd hang.

  • Fixed SPI driver PRS signal initialization; incorrect define was used but had no effect on existing devices.

Chip Enablement#

None.

Key Features#

New Features | Enhancements | Removed Features | Deprecated Features

New Features#

  • Added permanent memory allocation initialization for CPC in preparation for Series 3. sl_cpc_init_permanent_allocations; sl_cpc_init() continues to handle this for Series 2.

  • Added support for GCC Link Time Optimization (LTO).

Enhancements#

None.

Removed Features#

None.

Deprecated Features#

None.

API Changes#

New APIs | Modified APIs | Removed APIs | Deprecated APIs

New APIs#

New API Signature

Deprecated API replaced by this (if any)

sl_status_t sl_cpc_init_permanent_allocations(void)

None

Modified APIs#

None.

Removed APIs#

None.

Deprecated APIs#

None.

Bug Fixes#

ID Issue Description GitHub / Salesforce Reference (if any) Affected Software Variants, Hardware, Modes, Host Interfaces
1430454 Resolved race condition in UART code causing buffer errors. None All
1411410 Improved SPI bitrate configuration to make it optional. None All
1410876 Corrected nonce overflow detection logic in CPC protocol. None All
1375701 Fixed link time warnings in GCC LTO compilation for CPC sample apps. None All
1281660 Addressed xmodem bootloader detection causing CPCd hang. None All

Chip Enablement#

None.

Application Example Changes#

New Examples#

None.

Modified Examples#

None.

Removed Examples#

None.

Deprecated Examples#

None.

Known Issues and Limitations#

None.