Xilinx Vitis Drivers API Documentation
bram Documentation

If ECC is not enabled, this driver exists only to allow the tools to create a memory test application and to populate xparameters.h with memory range constants. In this case there is no source code.

If ECC is enabled, this file contains the software API definition of the Xilinx BRAM Interface Controller (XBram) device driver.

The Xilinx BRAM controller is a soft IP core designed for Xilinx FPGAs and contains the following general features:

  • LMB v2.0 bus interfaces with byte enable support
  • Used in conjunction with bram_block peripheral to provide fast BRAM memory solution for MicroBlaze ILMB and DLMB ports
  • Supports byte, half-word, and word transfers
  • Supports optional BRAM error correction and detection.

The driver provides interrupt management functions. Implementation of interrupt handlers is left to the user. Refer to the provided interrupt example in the examples directory for details.

This driver is intended to be RTOS and processor independent. Any needs for dynamic memory management, threads or thread mutual exclusion, virtual memory, or cache control must be satisfied by the layer above this driver.

Initialization & Configuration

The XBram_Config structure is used by the driver to configure itself. This configuration structure is typically created by the tool-chain based on HW build properties.

To support multiple runtime loading and initialization strategies employed by various operating systems, the driver instance can be initialized as follows:

  • XBram_CfgInitialize(InstancePtr, CfgPtr, EffectiveAddr) - Uses a configuration structure provided by the caller. If running in a system with address translation, the provided virtual memory base address replaces the physical address present in the configuration structure.

This API utilizes 32 bit I/O to the BRAM registers. With less than 32 bits, the unused bits from registers are read as zero and written as don't cares.

Ver   Who  Date     Changes

3.00a sa 05/11/10 Added ECC support 3.01a sa 01/13/12 Changed Selftest API from XBram_SelfTest(XBram *InstancePtr) to XBram_SelfTest(XBram *InstancePtr, u8 IntMask) and fixed a problem with interrupt generation for CR 639274 Modified Selftest example to return XST_SUCCESS when ECC is not enabled and return XST_FAILURE when ECC is enabled and Control Base Address is zero (CR 636581) Modified Selftest to use correct CorrectableCounterBits for CR 635655 Updated to check CorrectableFailingDataRegs in the case of LMB BRAM. Added CorrectableFailingDataRegs and UncorrectableFailingDataRegs to the config structure to distinguish between AXI BRAM and LMB BRAM. These registers are not present in the current version of the AXI BRAM Controller. 3.02a sa 04/16/12 Added test of byte and halfword read-modify-write 3.02a sa 04/16/12 Modified driver tcl to sort the address parameters to support both xps and vivado designs. 3.02a adk 24/4/13 Modified the tcl file to avoid warnings when ecc is disabled cr:705002. 3.03a bss 05/22/13 Added Xil_DCacheFlushRange in xbram_selftest.c to flush the Cache after writing to BRAM in InjectErrors API(CR #719011) 4.0 adk 19/12/13 Updated as per the New Tcl API's 4.1 sk 11/10/15 Used UINTPTR instead of u32 for Baseaddress CR# 867425. Changed the prototype of XBram_CfgInitialize API. ms 01/23/17 Modified xil_printf statement in main function for all examples to ensure that "Successfully ran" and "Failed" strings are available in all examples. This is a fix for CR-965028. ms 03/17/17 Added readme.txt file in examples folder for doxygen generation. 4.2 ms 04/18/17 Modified tcl file to add suffix U for all macro definitions of bram in xparameters.h ms 08/07/17 Fixed compilation warnings in xbram_sinit.c