Bus Master and PC Functions

General Description

Functions
cy_en_prot_status_t	Cy_Prot_ConfigBusMaster (en_prot_master_t busMaster, bool privileged, bool secure, uint32_t pcMask)
	Configures the allowed protection contexts, security (secure/non-secure) and privilege level of the bus transaction created by the specified master. More...
cy_en_prot_status_t	Cy_Prot_SetActivePC (en_prot_master_t busMaster, uint32_t pc)
	Sets the current/active protection context of the specified bus master. More...
uint32_t	Cy_Prot_GetActivePC (en_prot_master_t busMaster)

Function Documentation

Cy_Prot_ConfigBusMaster()

cy_en_prot_status_t Cy_Prot_ConfigBusMaster	(	en_prot_master_t	busMaster,
		bool	privileged,
		bool	secure,
		uint32_t	pcMask
	)

Configures the allowed protection contexts, security (secure/non-secure) and privilege level of the bus transaction created by the specified master.

Note

This function is applicable for both CPUSS ver_1 and ver_2.

Parameters

busMaster	Indicates which master needs to be configured. Refer to the CPUSS_MS_ID_X defines in the device config header file.
privileged	Boolean to define the privilege level of all subsequent bus transfers. True - privileged, False - not privileged. Note that this is an inherited value. If not inherited, then this bit will be used.
secure	Security setting for the master. True - Secure, False - Not secure.
pcMask	This is a 16 bit value of the allowed contexts, it is an OR'ed (|) field of the provided defines in cy_prot.h. For example: (CY_PROT_PCMASK1 | CY_PROT_PCMASK3 | CY_PROT_PCMASK4)

Note

The function accepts pcMask values from CY_PROT_PCMASK1 to CY_PROT_PCMASK15. But each device has its own number of available protection contexts. That number is defined by PERI_PC_NR in the config file.

Returns

Status of the function call.

Status	Description
CY_PROT_SUCCESS	The function completed successfully.
CY_PROT_FAILURE	The resource is locked.

Function Usage

    /* Scenario: CM0+ needs to be able to access resources protected with privileged, 
                 secure and set PC value (PC=0, PC=1 or PC=2) access settings */
    
    /* Configure the CM0+ bus master - privileged, secure, allow setting PC to PC=1 and PC=2 */
    if(CY_PROT_SUCCESS != Cy_Prot_ConfigBusMaster(CPUSS_MS_ID_CM0, true, true, CY_PROT_PCMASK1 | CY_PROT_PCMASK2))
    {
        /* Insert error handling */
    }

Cy_Prot_SetActivePC()

cy_en_prot_status_t Cy_Prot_SetActivePC	(	en_prot_master_t	busMaster,
		uint32_t	pc
	)

Sets the current/active protection context of the specified bus master.

Allowed PC values are 1-15. If this value is not inherited from another bus master, the value set through this function is used.

Note

This function is applicable for both CPUSS ver_1 and ver_2.

The function does not have access and returns an error for the secure CYB06xx7 devices.

Parameters

busMaster	The bus master to configure. Refer to the CPUSS_MS_ID_X defines in the device config header file.
pc	Active protection context of the specified master cy_en_prot_pc_t.

Note

that only those protection contexts allowed by the pcMask (which was configured in Cy_Prot_ConfigBusMaster) will take effect.

The function accepts pcMask values from CY_PROT_PC1 to CY_PROT_PC15. But each device has its own number of available protection contexts. That number is defined by PERI_PC_NR in the config file.

Returns

Status of the function call.

Status	Description
CY_PROT_SUCCESS	The function completed successfully.
CY_PROT_FAILURE	The resource is locked.

Function Usage

    /* Scenario: CM0+ needs to access a protected resources that requires PC=1 attribute */
    
    /* Configure the bus master to allow setting PC to PC=1 and PC=2 */
     Cy_Prot_ConfigBusMaster(CPUSS_MS_ID_CM0, true, true, CY_PROT_PCMASK1 | CY_PROT_PCMASK2);
    
    /* Get the active PC value of CM0+ */
    if(CY_PROT_PC1 != Cy_Prot_GetActivePC(CPUSS_MS_ID_CM0))
    {
        /* Set the CM0+ PC value to 1 */
        if(CY_PROT_SUCCESS != Cy_Prot_SetActivePC(CPUSS_MS_ID_CM0, CY_PROT_PC1))
        {
            /* Insert error handling */
        }
    }

Cy_Prot_GetActivePC()

uint32_t Cy_Prot_GetActivePC

(

en_prot_master_t

busMaster

)

Note

This function is applicable for both CPUSS ver_1 and ver_2.

Returns the active protection context of a master.

Parameters

busMaster

The bus master, whose protection context is being read. Refer to the CPUSS_MS_ID_X defines in the device config header file.

Returns

Active protection context of the master cy_en_prot_pc_t.

Function Usage

    /* Scenario: CM0+ needs to access a protected resources that requires PC=1 attribute */
    
    /* Configure the bus master to allow setting PC to PC=1 and PC=2 */
     Cy_Prot_ConfigBusMaster(CPUSS_MS_ID_CM0, true, true, CY_PROT_PCMASK1 | CY_PROT_PCMASK2);
    
    /* Get the active PC value of CM0+ */
    if(CY_PROT_PC1 != Cy_Prot_GetActivePC(CPUSS_MS_ID_CM0))
    {
        /* Set the CM0+ PC value to 1 */
        if(CY_PROT_SUCCESS != Cy_Prot_SetActivePC(CPUSS_MS_ID_CM0, CY_PROT_PC1))
        {
            /* Insert error handling */
        }
    }