Programming

Table of Contents

• PRU Firmware Development
  • Supported Languages
  • Example Project
  • Building Project
• PRU-ICSS Driver APIs (- R5F side)
  • Overview of APIs

PRU Firmware Development

Supported Languages

PRU firmware may be written in C code, or in assembly code, or can be a combination of both in a single example.

Refer for in detail reference:

• Instructions available: PRU Assembly Instruction User Guide
• Assembly Coding: PRU Assembly Language Tools
• C Coding: PRU Optimizing C/C++ Compiler

Example Project

To get started, follow along the empty example project included in the SDK at <sdk>/examples/pru_io/empty/, documentation at: Empty Project.

Building Project

Note

The PRU projects need TI-PRU-CGT to compile the sources into executable binary.

PRU-ICSS Driver APIs (- R5F side)

The following APIs are available for R5F core to initialize, manage and control PRU core. Refer PRUICSS for more details.

Overview of APIs

• Module-level Initialization and Deinitialization
  • APIs : PRUICSS_init(), PRUICSS_deinit()
  • Called automatically by SysConfig generated code if PRU-ICSS module is instantiated in SysConfig
  • PRUICSS_init() needs to be called before calling any other APIs
• Handle Initialization and Deinitialization
  • APIs : PRUICSS_open(), PRUICSS_close()
  • PRUICSS_open() function creates the handle for a PRUICSS instance. This handle is required for calling other APIs
  • PRUICSS_close() is used for deleting the handle
• Interrupt Controller Module Initialization
  • APIs : PRUICSS_intcInit()
  • This function does Interrupt-Channel-Host mapping
  • The interrupt controller (INTC) module maps interrupts coming from different parts of the device (mapped to PRUICSS instance) to a reduced set of interrupt channels.
  • More details
    • Section in MCU+ SDK Docs : https://software-dl.ti.com/mcu-plus-sdk/esd/AM64X/08_01_00_36/exports/docs/api_guide_am64x/DRIVERS_PRUICSS_PAGE.html#PRUICSS_INTC
    • TRM : Section _"6.4.7 PRU_ICSSG Local INTC"_ in Technical Reference Manual(TRM) of AM64x for more details on INTC module
• PRU Core Control – Enable, Disable, Reset
  • APIs : PRUICSS_enableCore(), PRUICSS_disableCore(), PRUICSS_resetCore()
• Memory Management APIs
  • APIs : PRUICSS_initMemory(), PRUICSS_writeMemory(), PRUICSS_readMemory()
  • Init API sets the memory to zero
  • APIs can be used for any of the following memories
    • Data RAM0/RAM1
    • IRAM for PRU0/PRU1/TX_PRU0/TX_PRU1/RTU_PRU0/RTU_PRU1
      • Note : This can not be updated if the respective core is enabled
    • Data RAM2 (Shared RAM)
  • One example usage is to load the IRAM using the protocol firmware headers provided in .h file format
• Event Management APIs
  • PRUICSS_registerIrqHandler() : This function registers an Interrupt Handler for an event
  • PRUICSS_sendEvent() : This function generates an INTC event
  • PRUICSS_waitEvent() : This function waits for a system event to happen
  • PRUICSS_clearEvent() : This function clears an INTC event
  • PRUICSS_sendWaitClearEvent() : This function generates an INTC event, waits for INTC event and clears an INTC event
• Information APIs
  • PRUICSS_getVersion() : Get PRUICSS version number from ICSSCFG_REVID register
  • PRUICSS_readEfuse() : Read the state of efuse bits from ICSSG_HWDIS_REG register
  • PRUICSS_getAttrs() : Return PRUICSS attributes like base addresses of different modules, their sizes, etc.
• Configuration APIs
  • IEP:
    • PRUICSS_setIepClkSrc() : Configure the source of the IEP clock to be either IEP CLK as the source or ICSSGn_CORE_CLK
    • PRUICSS_controlIepCounter() : Enable/Disable the counter in IEP module
    • PRUICSS_setIepCounterIncrementValue() : Set the default increment value for counter in IEP module
  • Constant Table:
    • PRUICSS_setConstantTblEntry() : Update the constant table for specified constant table entry which have write permissions
  • Others:
    • PRUICSS_setGpMuxSelect() : Set the GP Mux Select mode (GP/EnDat/MII/SD) for a specific PRU
    • PRUICSS_setGpiMode() : Sets the GPI mode for a specific PRU
    • PRUICSS_setSaMuxMode() : Set the G_MUX_EN mux field in ICSSG_SA_MX_REG register
    • PRUICSS_configureCycleCounter() : Enable/Disable the PRU Cycle Counter for a core
    • PRUICSS_setIcssCfgMiiMode() : Set the MII mode (MII/RGMII/SGMII) in MII_G_RT_ICSS_G_CFG register
    • PRUICSS_setIcssCfgTxFifo() : Configure the TX FIFO (L1/L2) to be used