Hello,
I'm working with i.MX8DX (Dual Core CortexA35 + CortexM4) with the following simplified caching system:

My need is to flush a cached memory area to RAM in order to be viewed by the M4 core, unfortunately this area maybe cached by Core 0 and…
Hello,
I'm working with i.MX8DX (Dual Core CortexA35 + CortexM4) with the following simplified caching system:

My need is to flush a cached memory area to RAM in order to be viewed by the M4 core, unfortunately this area maybe cached by Core 0 and…
Hi,
I have been reading about io coherency and the inner/outer shareability (SH bits in PTE). I kind of understand the concept of both but need help to connect the 2 concepts together. Lets assume a platform with (runs only one OS):
- CCI-400
- A53 Cluster…
The DCIMVAC represents a cache invalidate work. But one specific remark is that it will clean the data if the data is dirty before invalidation. Refer to followings
/******************************************************/
6.2.4 Data cache maintenance…
Hi,
I am working on access pcie bar in armv8-a cpu(cortex-A5x) powered soc. Right now, I encounter an issue about (maybe) coherent issue.
When I write data(4 bytes aligned) to pcie bar with ioremap_wc, there is some incorrect data. And it is correct…
Hi ,
I am working on ARM Multiprocessor. The Following is scenario for Cache coherency . Please let me know if it is valid.
1. Bring Core 1 out of reset.
2. Bring Core 2 out of reset.
3. Invalidate Core 2 data cache…
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…
Cleaning or invalidating the L1 cache and L2 cache will not be a single atomic operation. A core might therefore perform cache maintenance on a particular address in both L1 and L2 caches only as two discrete steps. If another core were to access the…
Hi Experts,
Which factor in processor decides whether it can be used in multi-core or not ?
Like as per my understanding A8 is used in single core whereas A9 is used in multi core. So which distinctive feature in A9 favors the multi core application ?
Hi Experts,
Is there any general feature available in the cortex processors to realize the cache lines by DMA through AXI ?
I found some features like CCI module available to provide this feature in multi-core environment. Other than that, is it possible…
Hi,
I'm trying to implement a spin-lock to synchronize the execution of all cores Cortex-A53 on my Xilinx-ZCU102 board, but I have some issues maybe due to a wrong configuration of the VMSA and cache coherence.
I'm writing bare-metal code, without…
Hi,
I have a system with a multiple quad core clusters with Cortex A-53 and the CCN-512. L1 through L2 are integrated caches where L3 is an outer cache in 8xHN-F of the CCN512.
My question is how should I interpret the shareability domain: inner, outer…
Currently working on Xilinx Zynq US+ soc where R5(2 cores in lock step) and A53 (4 cores) , PL and GPU are mounted onto a single chip.
so far we were using the concept of software based cache coherency mechanism to communicate between R5 and A53 worlds…
Hi,
according to this talk, cache maintenance should always be performed by VA and not by set/way except during boot or shutdown. However, invalidating/cleaning a block of data by VA requires a loop to run over the entire memory block (in steps equal…
Chinese Version 中文版: 扩展系统一致性 - 第 3 部分 - 性能提升和 CoreLink CCI-500 简介
This week we announced the launch of a new suite of IP designed to enhance the premium mobile experience. A central part of this suite is the ARM CoreLink CCI-500 Cache Coherent Inter…
Chinese Version中文版:扩展系统一致性 - 第 2 部分 - 实施、big.LITTLE、GPU 计算和企业级应用
This is the second part of a series of blogs about hardware coherency. In the first blog I introduced the fundamentals of cache coherency. This part talks about the implementation of hardware…
The Heterogeneous System Architecture (HSA) Foundation is a not-for profit consortium for SoC IP vendors, OEMs, academia, SoC vendors, OSVs and ISVs whose goal is to make it easier for software developers to…
Chinese Version 中文版:扩展系统一致性 - 第 1 部分 - 缓存一致性基本信息
The theme of TechCon 2013 was “Where intelligence connects” and in many ways hardware system coherency is an important part of connecting the intelligence of an SoC. This year I presented…
Hi,
I have board with two clusters, one has 4*A57 cores, and the other has 4*A53 cores.
The A57 cluster has its own L1 and L2 cache, A53 cluster also has its own L1 and L2 cache. Between the clusters there is a CCI.
There is no L3 cache. So the memory…
IO coherency also allows device to access coherent memory space. The only difference I noticed is that cache stashing connects device directly with cluster, however, IO coherency transactions need to go through system interconnect.
Dear All,
Technical data sheets for the ARM7500FE and ARM7100 say that:
"In the ARM Processor the cache will be searched regardless of the state of the C bit, only reads that miss the cache will be affected."
Now the question is that whether…
Greetings ARM community,
I have been tasked with cache maintenance. The necessity popped up because of DMA issues on USB.
As a quick (not perm solution) I used the invalidate all routine. While obviously not nominal in anyway
it does allow me…
Does Cortex-A12 not supprt AMBA4 ACE protocol?
The figure and description of the Cortex-A12 product page(http://www.arm.com/products/processors/cortex-a/cortex-a12-processor.php) shows as if it only supports "AMBA4 AXI Bus" is available bus interface…