IS200IGEHG1A机器人模块卡件
例如链接列表由32位原子元素组成。这些元素之一的原子更新需要同时更新整个32位值。对于任何主机来说，在一个时间点仅观察到16位的更新，然后在稍后的时间点观察到其他16位的升级是不可接受的。更复杂的系统需要支持更大的原子元素，特别是64位原子元素，以便主机可以使用基于这些更大原子元素的数据结构进行通信。9原子性9.2多拷贝原子性ARM IHI 0033B。b版权所有ARM Limited或其附属公司。保留所有权利。9-77 ID102715非机密9.2多拷贝原子性AHB5定义了Multi_copy_atomicity属性。定义此属性是为了指定系统提供多副本原子性。如果Multi_Copy_Atomicity属性设置为True，则系统定义为具有此属性。不支持Multi_Copy_Atomicity属性的系统的默认值为False。如果：•所有代理以相同的顺序观察到同一位置的写入，则系统定义为多副本原子系统。•对除发行人之外的代理人可观察到的位置的写入可由所有代理人观察到。通过避免使用转发缓冲区，可以确保多副本原子性，因为转发缓冲区可以使系统中的某些代理可见，但对所有代理都不可见。注意：在包含某种形式的硬件缓存一致性的系统中，存在确保多副本原子性的附加要求。本规范中未进一步详细讨论这些附加要求。9原子性9.2多拷贝原子性9-78版权所有ARM Limited或其附属公司。保留所有权利。ARM IHI 0033B.b非机密ID102715 ARM IHI 0023B.b版权所有ARM Limited或其附属公司。保留所有权利。10-79 ID102715非保密第10章用户信令本章描述了每个信道上的一组可选用户定义信号，称为用户信号。它包含以下部分：•第10-80页上的用户信号说明。•第10-81页上的用户信号互连建议。注：通常，本规范建议不使用用户信号。AHB协议没有定义这些信号的功能，如果两个组件以不兼容的方式使用相同的用户信号，这可能会导致互操作性问题。10用户信号10.1用户信号说明10-80版权所有ARM Limited或其附属公司。保留所有权利。ARM IHI 0033B.b非机密ID102715 10.1用户信号描述为每个信道定义的用户信号名称为：HAUSER地址信道用户信号。HWUSER写入数据通道用户信号。HRUSER读取数据通道用户信号。这些信号具有与相关信道相同的定时和有效性要求。对于数据信道用户信号，本规范建议：•用户比特数是接口宽度（字节）的整数倍。•每个字节的用户位以相邻位打包在一起。数据通道的用户位位置定义为：•每个数据字节有m个与之相关的用户信号。•数据总线宽度为n字节。•用户比特的总数是u，其中u＝m×n。字节y的用户信号，其中y＝0。。。（n–1），位于：•HWUSER[（（y×m）+（m–1））：（y×米）]•HRUSER[（y×m）+（m–1）：（y×m）]本规范建议在互连上包含用户信号，但无需在主设备或从设备上包含这些信号。本规范建议互连组件支持用户信号，以便在主组件和从组件之间传递。用户定义信号的宽度是执行定义的，并且对于每个信道可以是不同的。10用户信令10.2用户信号互连建议ARM IHI 0033B。b版权所有ARM Limited或其附属公司。保留所有权利。10-81 ID102715非机密10.2用户信号互连建议对于未经互连修改的传输，t
such as linked lists are made up of 32-bit atomic elements. An atomic update of one of these elements requires that the entire 32-bit value is updated at the same time. It is not acceptable for any master to observe an update of only 16-bits at one point in time, and then the update of the other 16-bits at a later point in time. More complex systems require support for larger atomic elements, in particular 64-bit atomic elements, so that masters can communicate using data structures that are based on these larger atomic elements. 9 Atomicity 9.2 Multi-copy atomicity ARM IHI 0033B.b Copyright ARM Limited or its affiliates. All rights reserved. 9-77 ID102715 Non-Confidential 9.2 Multi-copy atomicity AHB5 defines the Multi_Copy_Atomicity property. This property is defined to specify that a system provides multi-copy atomicity. A system is defined as having this property if the Multi_Copy_Atomicity property is set to True. A system that does not support the Multi_Copy_Atomicity property has the default value of False. A system is defined as being multi-copy atomic if: • Writes to the same location are observed in the same order by all agents. • A write to a location that is observable by an agent, other than the issuer, is observable by all agents. Multi-copy atomicity can be ensured by avoiding the use of forwarding buffers, which can make a transfer visible to some agents in a system, but not visible to all. Note Additional requirements exist to ensure multi-copy atomicity in systems that include some form of hardware cache coherency. These additional requirements are not discussed in further detail in this specification. 9 Atomicity 9.2 Multi-copy atomicity 9-78 Copyright ARM Limited or its affiliates. All rights reserved. ARM IHI 0033B.b Non-Confidential ID102715 ARM IHI 0033B.b Copyright ARM Limited or its affiliates. All rights reserved. 10-79 ID102715 Non-Confidential Chapter 10 User Signaling This chapter describes the set of optional user defined signals, on each channel, called the User signals. It contains the following sections: • User signal description on page 10-80. • User signal interconnect recommendations on page 10-81. Note Generally, this specification recommends that the User signals are not used. The AHB protocol does not define the function of these signals and this can lead to interoperability issues if two components use the same User signals in an incompatible way. 10 User Signaling 10.1 User signal description 10-80 Copyright ARM Limited or its affiliates. All rights reserved. ARM IHI 0033B.b Non-Confidential ID102715 10.1 User signal description The User signal names defined for each channel are: HAUSER Address channel User signals. HWUSER Write data channel User signals. HRUSER Read data channel User signals. These signals have the same timing and validity requirements as the associated channel. For data channel User signals, this specification recommends that: • The number of User bits is an integer multiple of the width of the interface in bytes. • The User bits for each byte are packed together in adjacent bits. The location of the User bits for a data channel is defined as: • Each data byte has m User signals associated with it. • The data bus width is n bytes. • The total number of User bits is u where u = m × n. The user signals for byte y, where y = 0 ... (n – 1), are located at: • HWUSER[((y × m) + (m – 1)):(y × m)] • HRUSER[((y × m) + (m – 1)):(y × m)] This specification recommends including User signals on an interconnect, however, there is no requirement to include them on masters or slaves. This specification recommends that interconnect components include support for User signals so that they can be passed between master and slave components. The width of the User defined signals is IMPLEMENTATION DEFINED and can be different for each of the channels. 10 User Signaling 10.2 User signal interconnect recommendations ARM IHI 0033B.b Copyright ARM Limited or its affiliates. All rights reserved. 10-81 ID102715 Non-Confidential 10.2 User signal interconnect recommendations For transfers that are not modified by the interconnect, t
