# SysLib (System Library)¶

group group_syslib

The system libraries provide APIs that can be called in the user application to handle the timing, logical checking or register.

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

The SysLib driver contains a set of different system functions. These functions can be called in the application routine. Major features of the system library:

• Delay functions

• Assert and Halt

• Assert Classes and Levels

• A software reset

• An API to invalidate the flash cache and buffer

• Data manipulation macro

• A variable type definition from MISRA-C which specifies signedness

• Cross compiler compatible attributes

• Getting a silicon-unique ID API

• Setting wait states API

• Resetting the backup domain API

• APIs to serve Fault handler

Configuration Considerations

Assertion Usage Use the CY_ASSERT() macro to check expressions that must be true if the program is running correctly. It is a convenient way to insert sanity checks. The CY_ASSERT() macro is defined in the cy_utils.h file, which is part of the Cypress Core Library (core-lib)

. The macro behavior is as follows: if the expression passed to the macro is false, the CPU is halted.

Starting from the driver version 2.50, the CY_ASSERT macro was moved to the Cypress Core Library (core-lib). Also, the CY_ASSERT implementation was changed not to call

Cy_SysLib_AssertFailed() function, so user application that relied on that should take this change into account.

The PDL source code uses this assert mechanism extensively. It is recommended that you enable asserts when debugging firmware. Assertion Classes and Levels The Cypress Core Library defines three assert classes, which correspond to different kinds of parameters. There is a corresponding assert “level” for each class.

 Class Macro Level Macro Type of check CY_ASSERT_CLASS_1 CY_ASSERT_L1 A parameter that could change between different PSoC devices (e.g. the number of clock paths) CY_ASSERT_CLASS_2 CY_ASSERT_L2 A parameter that has fixed limits such as a counter period CY_ASSERT_CLASS_3 CY_ASSERT_L3 A parameter that is an enum constant
Firmware defines which ASSERT class is enabled by defining CY_ASSERT_LEVEL. This is a compiler command line argument, similar to how the DEBUG / NDEBUG macro is passed.

Enabling any class also enables any lower-numbered class. CY_ASSERT_CLASS_3 is the default level, and it enables asserts for all three classes. The following example shows the command-line option to enable all the assert levels:
-D CY_ASSERT_LEVEL=CY_ASSERT_CLASS_3


note

The use of special characters, such as spaces, parenthesis, etc. must be protected with quotes.

After CY_ASSERT_LEVEL is defined, firmware can use one of the three level macros to make an assertion. For example, if the parameter can vary between devices, firmware uses the L1 macro.

CY_ASSERT_L1(clkPath < SRSS_NUM_CLKPATH);

If the parameter has bounds, firmware uses L2.
CY_ASSERT_L2(trim <= CY_CTB_TRIM_VALUE_MAX);

If the parameter is an enum, firmware uses L3.
CY_ASSERT_L3(config->LossAction <= CY_SYSCLK_CSV_ERROR_FAULT_RESET);

Each check uses the appropriate level macro for the kind of parameter being checked. If a particular assert class/level is not enabled, then the assert does nothing.