Data Cache Parity Error
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detects, handles, reports, and corrects cache memory errors. Memory errors detected with parity or ECC have Fault Status Register (FSR) values to distinguish them from other abort causes.This section describes:Error build optionsAddress decoder faultsHandling cache parity errorsHandling cache ECC parity error 5x5 errorsErrors on instruction cache readErrors on data cache readErrors on data cache writeErrors memory parity error on evictionsErrors on cache maintenance operations.Error build optionsThe caches can detect and correct errors depending on the build options used parity error system halted in the implementation. The build options for the instruction cache can be different to the data cache.If the parity build option is enabled, the cache is protected by parity bits. For both parity error cisco the instruction and data cache, the data RAMs include one parity bit per byte of data. The tag RAM contains one parity bit to cover the tag and valid bit.If the ECC build option is enabled:The instruction cache is protected by a 64-bit ECC scheme. The data RAMs include eight bits of ECC code for every 64 bits of data. The tag RAMs include seven bits
Parity Error Detection
of ECC code to cover the tag and valid bit.The data cache is protected by a 32-bit ECC scheme. The data RAMs include seven bits of ECC code for every 32 bits of data. The tag RAMs include seven bits of ECC code to cover the tag and valid bit. The dirty RAM includes four bits of ECC to cover the dirty bit and the two outer attributes bits of each cache line.Address decoder faultsThe error detection schemes described in this section provide protection against errors that occur in the data stored in the cache RAMs. Each RAM normally includes a decoder that enables access to that data and, if an error occurs in this logic, it is not normally detected by these error detection schemes. The processor includes features that enable it to detect some address decoder faults. If you are implementing the processor and require these features, contact ARM to discuss the features and your requirements.Handling cache parity errorsTable 8.2 shows the behavior of the processor on a cache parity error, depending on bits [5:3] of the ACTLR, see c1, Auxiliary Control Register. Table 8.2. Cache parity error behaviorValueBehaviorb000Generate abort on parity errors[a], force write-through, enable hardwar
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Nmi Parity Error
Languages Download Options PDF (259.4 KB) View with Adobe Reader pci parity error on a variety of devices Updated:Jul 15, 2013 Document ID:116135 Document ID: 116135 Updated: Jul 15, parity error 4x4 2013 Contributed by Shawn Wargo, Cisco Engineering. Download PDF Print Feedback Related ProductsCisco Catalyst 6500 Series Switches ContentsIntroductionBackgroundSoft ErrorsHard ErrorsCommon Error MessagesProcessorRAMASICLatest AdvancementsProcessorRAMASICSoftwareMSFC http://infocenter.arm.com/help/topic/com.arm.doc.ddi0363g/Chdgfjac.html IBC Reset6700 Series 'Single-Bit Parity Error' ResetRecommendationsSoft Errors (SEU)Environmental AuditLatest Firmware (Rommon)Thumb ScrewsHard Errors (Malfunction)Hardware (MTBF and EOL) AuditHardware DiagnosticsRelated Cisco Support Community DiscussionsIntroductionThis document describes soft and hard parity errors, explains common error messages, and recommends methods that help you avoid or minimize parity errors. Recent improvements in hardware and http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/116135-trouble-6500-parity-00.html software design reduce parity problems as well. BackgroundWhat is a processor or memory parity error?Parity checking is the storage of an extra binary digit (bit) in order to represent the parity (odd or even) of a small amount of computer data (typically one byte) while that data is stored in memory. The parity value calculated from the stored data is then compared to the final parity value. If these two values differ, this indicates a data error, and at least one bit must have been changed due to data corruption.Within a computer system, electrical or magnetic interference from internal or external causes can cause a single bit of memory to spontaneously flip to the opposite state. This event makes the original data bits invalid and is known as a parity error.Such memory errors, if undetected, may have undetectable and inconsequential results or may cause permanent corruption of stored data or a machi
challenged and removed. (January 2013) (Learn how and when to remove this template message) 7 bits of data (count of 1-bits) 8 bits including parity even odd 0000000 0 00000000 00000001 1010001 3 10100011 10100010 1101001 4 11010010 11010011 https://en.wikipedia.org/wiki/Parity_bit 1111111 7 11111111 11111110 A parity bit, or check bit, is a bit added to http://stackoverflow.com/questions/21315342/cortex-a9-cache-parity a string of binary code that indicates whether the number of 1-bits in the string is even or odd. Parity bits are used as the simplest form of error detecting code. There are two variants of parity bits: even parity bit and odd parity bit. In the case of even parity, for a given set of bits, parity error the occurrences of bits whose value is 1 is counted. If that count is odd, the parity bit value is set to 1, making the total count of occurrences of 1's in the whole set (including the parity bit) an even number. If the count of 1's in a given set of bits is already even, the parity bit's value is 0. In the case of odd parity, the coding is data cache parity reversed. For a given set of bits, if the count of bits with a value of 1 is even, the parity bit value is set to 1 making the total count of 1's in the whole set (including the parity bit) an odd number. If the count of bits with a value of 1 is odd, the count is already odd so the parity bit's value is 0. Even parity is a special case of a cyclic redundancy check (CRC), where the 1-bit CRC is generated by the polynomial x+1. If the parity bit is present but not used, it may be referred to as mark parity (when the parity bit is always 1) or space parity (the bit is always 0). Parity bits are generally applied to the smallest units of a communication protocol, typically 8-bit octets (bytes), although they can also be applied separately to an entire message string of bits. The decimal math equivalent to the parity bit is the Check digit. Contents 1 Parity 2 Error detection 3 Usage 3.1 RAID 4 History 5 See also 6 References 7 External links Parity[edit] In mathematics, parity refers to the evenness or oddness of an integer, which for a binary number is determined only by the least significant bit. In telecommunica
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Cortex-A9 Cache Parity up vote 1 down vote favorite I'm using a cortex-a9 based design ( Altera Cyclon-V ) with a pl310 l2 cache controller. When I'm enabling the "parity enabled" in the PL310 AUX register, I get failures ( interrupt indicating cache parity issue ) . When I'm keeping Parity disabled (default value) system runs fine, no error\abort of bad data. Any ideas why this might happen? arm cpu-cache altera parity share|improve this question edited Jan 5 '15 at 20:36 artless noise 12k43867 asked Jan 23 '14 at 17:30 user3087632 162 Some PL310 have the extra parity cache bits and some don't. It is obviously less SRAM cells to not have parity so I guess that most designs do not populate it. If you enable it and there is no parity cells on chip, you will get an error. You have to look at the cache ID registers. For the comments, it seems the OP has the parity bits in the design. –artless noise Jan 5 '15 at 20:37 add a comment| 2 Answers 2 active oldest votes up vote 0 down vote A few things that you should check up on is errata for the device that you are using and any specific recommendations on the operating frequency of the CPU to use certain features. Early version of PL310 had a few bugs around the parity feature and a quick search also turns up the following document from Altera for the Cyclon-V devices. It recommends certain operating frequencies when using the ECC feature and the issue that you are seeing could be similar. share|improve this answer answered Jan 24 '14 at 16:23 vPraetor 113211 Thanks . I'm aware of this ECC bug. Altera Cyclone V offers both Parity Check ( on Tag RAM ) and ECC ( on Data RAM ). we are aware of the ECC Errata. The Aborts we are seeing are a result of Parity failures on Tag RAM. I've modi