参数资料
型号: TSB14C01MHV
英文描述: IC APEX 20KE FPGA 160K 484-FBGA
中文描述: 收发器
文件页数: 30/35页
文件大小: 224K
代理商: TSB14C01MHV
6
10
detect the subaction gap before the bus is asserted by another node (upon detecting a subaction gap). The
duration of the subaction gap ensures that another node asserting the bus after an acknowledge gap has
been detected by this time.
Arbitration Reset Gap
Appears before asynchronous transfers when the fairness interval starts. A node
should detect the occurrence of an arbitration reset gap after the bus has been in an unasserted state for
at least 28 arbitration clock times (approximately 569.66 ns), but should not assert the bus until a total of
32 arbitration clock times (approximately 651.04 ns) have occurred. This requirement ensures that a node
is given adequate time to detect the arbitration reset gap before the bus is asserted by another node (upon
detecting an arbitration reset gap). The duration of the arbitration reset gap ensures that another node
asserting the bus after a subaction gap or an acknowledge gap has been detected by this time.
If a node is waiting for the occurrence of a particular gap and the bus has become idle for the specified time
(e.g., 32 arbitration clock times for an arbitration reset gap), the node detects the gap and asserts the bus.
An asserted signal propagates through the node decision/transceiver circuitry and onto the bus soon
enough to allow arbitration to occur properly.
6.3
Arbitration Sequence
The TSB14AA1A uses a particular arbitration sequence to arbitrate the bus between competing modules. The
sequence used consists of a 4-bit priority field and a 6-bit arbitration number field.
6.3.1
Priority
Within the arbitration sequence, the arbitration number is preceded by four bits that define a priority level. The method
by which priority is assigned is to be determined by the system integrator with two exceptions. The lowest priority (all
zeros) is reserved for fair arbitration and the highest priority (all ones) is reserved for cycle start requests. This allows
14 priority levels to be used for the urgent arbitration process.
The use of an urgent priority class allows nodes to be granted a large portion of the bandwidth on the bus. High priority
nodes are granted the bus before lower priority nodes during urgent allocation of the bus, allowing such nodes to be
granted more bandwidth.
In order to ensure forward progress, the lowest priority level is reserved for fair arbitration. This allows all nodes
arbitrating with this priority level to be allowed one fair access to the bus for each fairness interval. For fair arbitration,
the value of the arbitration number has a minimal impact on the allocation of the bus. Although nodes with higher
arbitration numbers are granted the bus sooner, there is only a small decrease in latency.
6.3.2
Arbitration Number
The arbitration sequence uses a unique arbitration number for each module. This 6-bit number is the same as the
node Physical_ID. When less than 6-bits are provided for the arbitration number, they occupy the MSBs of the
arbitration number. The remaining bits are zero-filled. The MSBs are transmitted first.
NOTE:
If the serial bus is contained within a host backplane, it is expected that the arbitration
number (i.e., Physical_ID) is set by the host backplane at power up (e.g., with a built-in slot
identifier or configuration mechanism).
This number is software programmable to facilitate testing and to allow for consistent system operation and
repeatability.
相关PDF资料
PDF描述
TSB14C01HV 5-V IEEE 1394-1995 BACKPLANE TRANSCEIVER/ARBITER
TSB21LV03MHV IC APEX 20KE FPGA 200K 484-FBGA
TSB21LV03CHV IEEE 1394-1995 TRIPLE-CABLE TRANSCEIVER/ARBITER
TSB2203X6MMX30M IC APEX 20KE FPGA 200K 240-PQFP
TSB2204.5X12MMX20M IC APEX 20KE FPGA 200K 240-PQFP
相关代理商/技术参数
参数描述
TSB14C01PM 制造商:Rochester Electronics LLC 功能描述:- Bulk
TSB15 制造商:未知厂家 制造商全称:未知厂家 功能描述:EURO TERMINAL BLOCKS
TSB150002DS 制造商:TE Connectivity 功能描述:
TSB150004DS 制造商:TE Connectivity 功能描述:Conn Europa Terminal Blocks 8 POS 13.5mm Screw ST Cable Mount 40A/Contact
TSB150005 功能描述:栅栏接线端子 5P TERM BLOCK 13.5MM 300V 40A RoHS:否 制造商:TE Connectivity / AMP 产品:Barrier Terminal Blocks 系列: 类型:Dual Barrier, Flat Block without Mounting Ears 节距:9.53 mm 位置/触点数量:2 线规量程:22-12 电流额定值:20 A 电压额定值:300 V 安装风格:Through Hole 安装角:Vertical 端接类型:Screw 触点电镀:Tin