eFuse (Electronic Fuses)

General Description

Electronic Fuses (eFuses) are non-volatile memory where each bit is one-time programmable (OTP).

The functions and other declarations used in this driver are in cy_efuse.h. You can include cy_pdl.h to get access to all functions and declarations in the PDL.

The eFuse driver enables reading the state of any bit. The eFuse driver does not support writing to eFuse memory. Writing an eFuse bit is typically done by a production programmer.

One eFuse macro consists of 256 bits (32 * 8). PSoC devices have up to 16 eFuse macros; consult the device-specific datasheet to determine how many macros a device has. These are implemented as a regular Advanced High-performance Bus (AHB) peripheral with the following characteristics:

• eFuses are used to control the device life-cycle stage (NORMAL, SECURE, and SECURE_WITH_DEBUG) and the protection settings;
• eFuse memory can be programmed (eFuse bit value changed from '0' to '1') only once; if an eFuse bit is blown, it cannot be cleared again;
• fuses are programmed via the PSoC Programmer tool that parses the hex file and extracts the necessary information; the fuse data must be located at the dedicated section in the hex file. For more details see PSoC 6 Programming Specifications

Configuration Considerations

The eFuse driver provides the simplest way to read eFuse memory. No configuration is needed.

More Information

Refer to the technical reference manual (TRM) and the device datasheet.

MISRA-C Compliance

MISRA Rule	Rule Class (Required/Advisory)	Rule Description	Description of Deviation(s)
11.5	R	Dangerous pointer cast results in loss of volatile qualification.	The removal of the volatile qualification inside the function has no side effects.

Changelog

Version	Changes	Reason for Change
1.10.3	Minor documentation updates.	Documentation enhancement.
1.10.2	Fix driver header path.	Folder structure changed.
1.10.1	Added header guard CY_IP_MXEFUSE.	To enable the PDL compilation with wounded out IP blocks.
1.10	Flattened the organization of the driver source code into the single source directory and the single include directory.	Driver library directory-structure simplification.
1.0	Initial version

API Reference
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	Functions
	Data Structures
	Enumerated Types