Simplicity SDK Platform - CPC Version 4.8.4 - Release Notes (Nov 4, 2026)#
Simplicity SDK Platform Version 6.0.3
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 in 4.8.4#
None.
Added in 4.8.3#
None.
Added in 4.8.0#
Added soft reset capability allowing the host to reset the device without performing a hard reset (for future usage).
Removal of legacy workaround in the secondary SPI driver for MMLDMA SYNC descriptor.
API Changes#
None.
Bug Fixes#
Fixed in 4.8.4#
Secondary (MCU): Fixed detection of a misconfiguration where the SPI driver RX queue size is smaller than the CPC RX buffer count.
Secondary (MCU): Fixed an issue where the Power Manager sleep callback did not correctly detect pending deferred work in bare-metal mode.
Host (CPC daemon): Fixed an XMODEM buffer underflow and out-of-bounds read during firmware updates when the RCP was already in bootloader mode.
Fixed in 4.8.3#
Secondary (MCU) fix: switching from UART recommended interface to SPI recommended interface should now build correctly.
Fixed an issue that occurred when an endpoint handle is opened in one thread and closed in another. The endpoint handle could be seen in an inconsistent state from the opening thread.
Fixed in 4.8.0#
Host (CPC daemon) fixes: corrected CLI option handling for WSTK IP, improved WSTK configuration parsing, restored missing unit/perf/multithreading test scripts, and resolved a compilation error caused by version struct changes.
Chip Enablement#
None.
Key Features#
New Features | Enhancements | Removed Features | Deprecated Features
New Features#
Added in 4.8.4#
None.
Added in 4.8.3#
None.
Added in 4.8.0#
Soft reset capability (for future usage).#
Added the ability for the host to reset the device without performing a hard reset. This feature is reserved for future functionality and provides a more graceful reset mechanism.
Enhancements#
Added in 4.8.4#
None.
Added in 4.8.3#
None.
Added in 4.8.0#
Secondary SPI driver: removed workaround for MMLDMA SYNC descriptor bug.#
Removed a legacy workaround in the SPI secondary driver after upstream descriptor fixes, reducing code complexity and potential maintenance overhead.
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) |
|---|---|
None. | None. |
Modified APIs#
None.
Removed APIs#
None.
Deprecated APIs#
None.
Bug Fixes#
Fixed in 4.8.4#
| ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
| N/A | Secondary (MCU): Added detection of a misconfiguration where the SPI driver's RX_QUEUE_SIZE is smaller than CPC's RX_BUFFER_MAX_COUNT. | None. | Software: CPC Secondary SPI |
| N/A | Secondary (MCU): Fixed pending work detection in the Power Manager callback sl_cpc_is_ok_to_sleep() in bare-metal mode. The callback could allow the device to sleep while deferred work was still pending. | None. | Software: CPC Secondary; Mode: Bare-metal with Power Manager |
| N/A | cpc: Fixed an XMODEM buffer underflow and out-of-bounds read in CPCd that could cause crashes during firmware updates when the RCP is already in bootloader mode. | None. | Software: Linux host CPC daemon; Mode: Firmware update (XMODEM) |
Fixed in 4.8.3#
| ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
| 1571482 | Secondary (MCU): switching from UART recommended interface to SPI recommended interface should now build correctly | None. | Software: CPC Secondary SPI |
Fixed in 4.8.0#
Services (Host / CPC daemon)#
| ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
| N/A | cpc: Fixed CLI handling in CPCd where --wireless-kit-ip was not recognized, ensuring both -w and --wireless-kit-ip function correctly. | None. | Software: Linux host CPC daemon; Hardware: WSTK; Mode: WSTK validation; Host Interface: Board controller IP over network |
| N/A | cpc: Improved parsing and output formatting for WSTK configuration (-w) in CPCd to reflect accurate speeds and handshake reporting. | None. | Software: Linux host CPC daemon; Hardware: WSTK; Mode: WSTK configuration; Host Interface: Board controller |
Chip Enablement#
None.
Application Example Changes#
New Examples#
None.
Modified Examples#
None.
Removed Examples#
None.
Deprecated Examples#
None.
Known Issues and Limitations#
None.