• ARMv7-A: What is "Fault not on a stage 2 translation for a stage 1 translation table walk"?

    Takumi Shimada
    Takumi Shimada

    Hi all,

    I'm trying to boot Linux on my hypervisor like environment.

    In booting process, unexpected hyper trap was occurred and became hyp mode.

    In hyp mode, the Hyp Syndrome Register (HSR) value is 0x93830006.

    According to the manual, this meant "Fault…

    • Answered
    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • what are the main differences between cortex A7, A9, A53

    aaa
    aaa

    What are the main/important features added/updated?

    Thank you.

    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Read allocate will impact bzero performance or not

    Ron
    Ron

    I'm trying to understand read allocate mode in cortex A7 core. From description of Read allocate mode in TRM of Cortex A7 core, my understanding is that bzero will downgrade memset performance while memset was done with consecutive memory.  For example…

    • Answered
    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • How to avoid bus error while using neon instruction vld2.32 on cortex a7?

    Katta Phani Kumar
    Katta Phani Kumar

    Hi, I am using imx6ul board which has cortex a7 processor. I am using ffmpeg .s files which has assembly code to integrate into our project to speed up the code.  Here is the ffmpeg code in the file mdct_neon.S.

    #include "asm.S"
    .fpu neo…

    • Answered
    • 9335.zip
    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • NE10-Library -> FIR-Filter cycle counts: C-version faster than NEON-version?

    CFriebel
    CFriebel

    Hi,

    i'm currently trying to measure cycle counts for FIR-filtering with the NE10 library. I'm using a Raspberry Pi 2 with ARM Cortex-A7 running on Raspbian as a target.

    I activated the Cortex-A7 performance counter register to read out the cycles…

    • Answered
    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Using the whole Cortex-A L2 Cache without external memory

    Laurent
    Laurent

    I'm thinking about using a cortex-a7 in "bare-metal" where I don't need much memory, so i'd like to avoid using external memory.

    The CPU boots from an external 4MBytes SPI NOR FLASH chip.

    It has 512 KBytes of L2 cache and 32 KBytes…

    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Barriers in in-order cores like cortex-A53, A7

    oootha
    oootha

    Hi experts!

    As you know, power efficient arm like cortexA7, A53 has in-order pipleline.
    However as far as I understanding, Barriers like dmb, dsb, isb are related with out-of-order memory access.
    But barriers are even used in in-order cpus.
    What is for?
    Can…

    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • How to configure L2 cache in Cortex-A7

    Cherma Rajan
    Cherma Rajan

    Hi all,

    I am working on OrangePi board. The board configuration is,

    • Quad-Core ARM Cortex-A7, 1.6 GHz
    • 32 KB L1 I-Cache and 32 KB L1 D-Cache per core
    • 512 KB L2-Cache

    I have few queries related to Cache memory,

    1. How to disable L2 cache of Cortex-A7 in…
    • Answered
    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • SGIs in AMP Configuration with Non-SMP Linux /RTOS

    Shafique
    Shafique

    I am trying to run two Cortex-A7s in AMP configuration with Linux running on one core (SMP disabled) and baremetal/RTOS running on other core. I am having difficulty in setting up SGIs (IPIs) between the two cores. I am at a point where both of the cores…

    • Answered
    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • voltage levels for dvfs

    Hergys
    Hergys

    Hello,

    i was wondering if the voltage levels for dvfs states are fixed at the design time. For example for Cortex A7 or A15. Is this information available?

    Thank you.

    • over 4 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • MOESI state encoding of Cortex-A7

    Isa
    Isa

    Hi,

    I am looking at Cortex-A7 TRM, In "Direct Access to Internal Memory"

    we can see several information regarding a cache line. Those are:

    1. Current data in cache

    2. its 4-bit MOESI state,

    3. Outer Memory Attribute

    4. its tag

    5. NS State.

    However…

    • Answered
    • over 3 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Raspberry Pi 2 JTAG error on memory access

    Alessandro
    Alessandro

    Hi all,

    I am trying to connect to the RPi2 JTAG.

    I have the following setup

    - Raspberry Pi 2 running Raspbian 8.0 (Jessie)

    - OpenOCD 0.9.0 with a J-Link EDU connected to a Ubuntu system.

    I setup the GPIO in order to expose the JTAG interface and the…

    • Answered
    • over 3 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Is there any available data about the PPA comparison b/w Cortex-A7 and Cortex-A53

    Shane Yu
    Shane Yu

    Performance (DMIPS/CoreMark/SpecInt, etc.), Power and Area comparison on an apple-to-apple basis? Thanks a lot!

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • ACTLR[1] question in Cortex-A serias SOC

    chinatiger
    chinatiger

    hi, experts:

    I found ACTLR register definition is different between Cortex-A7 and Cortex-A9.

    I have some questions about out cache concept in Cortex-A7.
    1. Some program disable outer cache by setting ACTLR[1] = 0.

       So, is it only available with Cortex-A9…

    • Answered
    • over 6 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Cortex-A7 initialization code & TrustZone/ Secure Boot

    Vincent Siles
    Vincent Siles

    Hi,

    I just got a raspberry pi 2 and I'd like to play with Trustzone.

    People on the Raspberry forum http://www.raspberrypi.org/forums/viewtopic.php?p=697474#p697474 explained me how to

    get my hand on the boot of the 4 core A7 CPU, and I managed to boot…

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • How does128Byte WriteLineUnique transaction map to a cache with 64Byte cache line size?

    Hanan
    Hanan

    Hello,

    I have an IP with an ACE-Lite I/F which can issue a 128Byte write transaction with a "WriteLineUnique" type. I  the system there will be a cortex A7 master(64bytes cache line). My question is: in case of such transaction (WriteLineUnique with 128bytes…

    • Answered
    • over 6 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • MRS/MSR (Banked register)

    Juha Aaltonen
    Juha Aaltonen

    What can be accessed by MRS/MSR in user mode?

    In ARMv7-A/R ARM there is an encoding for ARMv7VE (A1):

    B9.3.10      MSR (Banked register)
    cond  0 0 0 1 0 R 0 0        M1      …
    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Bit 22 in some LD/ST instructions (Cortex-A7)

    Juha Aaltonen
    Juha Aaltonen

    I wonder if the bit 22 has some function in instructions like LDRH, STRH, LDRSBT, LDRD, ... (bits 27, 26, 25 = 0, 0, 0)?

                               22…
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Still more stupid questions on Cortex-A7 instruction set

    Juha Aaltonen
    Juha Aaltonen

    I've beem constructing a list of Cortex-A7 ARM-instructions, and there are some questions I haven't found

    an answer to in ARMv7-A/R ARM Issue C.

    How is this special?

    LDRD<c>_<Rt>,_<Rt2>,_<label>_LDRD<c>_<Rt>,_<Rt2>,_[PC,_#-0]_Special_case…
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Questions about Generic Timer in ARMv8

    wangchj
    wangchj

    When two clusters(Big/Little) exist in SoC, the timer can be used to support Synchronization between two clusters.

    But How to understand "Synchronization", anybody can tell me some typical application context? I am really confused......

    And, if…

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • If a region is marked as non-cacheable, will the CPU also first check the cache when CPU want to access the region?

    Kun.Niu
    Kun.Niu

    If a region is marked as non-cacheable, will the CPU also first check the cache when CPU want to access the region?

    In cortex-A7 spec, it says" the core hardware will check all instruction fetches and data reads or writes in the cache, although obviously…

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Where can I find the cortex-A7 related 8 stages pipeline docments?

    Kun.Niu
    Kun.Niu

    Where can I find the cortex-A7 related 8 stages pipeline docments?

    I have found some docments about this but all are too brief, so I want ask where can I find the detailed docments?

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • In cortex-A7 it has 8 stages pipeline, so PC's value is current program address add how many?

    Kun.Niu
    Kun.Niu

    In cortex-A7 it has 8 stages pipeline, so PC's value is current program address add how many bytes?

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Where can I find the docments about how the ARM cortex-A series pipeline works?

    Kun.Niu
    Kun.Niu

    Where can I find the docments about how the ARM cortex-A series pipeline works?

    Such as the first step of the pipeline do what and the second step of the pipeline do what, and also the Cortex-A series has different pipelines(such as cortex-A7 is different…

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
  • Cortex-A7 structure can support max to 4 cores, I want ask the 4 cores have 4 part copy of the registers(37 registers * 4)?

    Kun.Niu
    Kun.Niu

    Cortex-A7 structure can support max to 4 cores, I want ask the 4 cores have 4 part copy of the registers(37 registers * 4)?

    In other words, each core have the same 37 registers or the 4 cores share the 37 registers?

    • Answered
    • over 5 years ago
    • Processors
    • Cortex-A / A-Profile forum
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