- 您现在的位置：买卖IC网 > PDF目录299575 > OR3T306S240I-DB (LATTICE SEMICONDUCTOR CORP) FPGA, 196 CLBS, 48000 GATES, PQFP240 PDF资料下载
参数资料
| 型号： | OR3T306S240I-DB |
| 厂商： | LATTICE SEMICONDUCTOR CORP |
| 元件分类： | FPGA |
| 英文描述： | FPGA, 196 CLBS, 48000 GATES, PQFP240 |
| 封装： | PLASTIC, SQFP-240 |
| 文件页数： | 185/203页 |
| 文件大小： | 1368K |
| 代理商： | OR3T306S240I-DB |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页第120页第121页第122页第123页第124页第125页第126页第127页第128页第129页第130页第131页第132页第133页第134页第135页第136页第137页第138页第139页第140页第141页第142页第143页第144页第145页第146页第147页第148页第149页第150页第151页第152页第153页第154页第155页第156页第157页第158页第159页第160页第161页第162页第163页第164页第165页第166页第167页第168页第169页第170页第171页第172页第173页第174页第175页第176页第177页第178页第179页第180页第181页第182页第183页第184页当前第185页第186页第187页第188页第189页第190页第191页第192页第193页第194页第195页第196页第197页第198页第199页第200页第201页第202页第203页
82
Lattice Semiconductor
Data Sheet
November 2006
ORCA Series 3C and 3T FPGAs
Programmable Clock Manager (PCM)
(continued)
High-Speed Internal Processing with Slow I/Os
The PCM PLL mode provides two outputs, one sent to
the global system clock routing of the FPGA and the
other to the ExpressCLK(s) that serve the FPGA I/Os.
The ExpressCLK output of the PCM has a divide capa-
bility (DIV2) that the system clock output does not. This
feature allows an input clock to be multiplied up to a
higher frequency for high-speed internal processing,
and also allows the ExpressCLK output to be divided
down to a lower frequency to accommodate off-FPGA
data transfers. For example, a 10 MHz input clock may
be multiplied (see Clock Multiplication in the Phase-
Locked Loop (PLL) Mode subsection) to 25 MHz (DIV0
= 4, DIV1 = 5, DIV2 = 2) and output to the FPGA
ExpressCLK
. This allows the I/Os of the circuit to run at
25 MHz ((2 * 5)/4 * 10 MHz). The system clock will run
at DIV2 times the ExpressCLK rate, which is 2 times
25 MHz, or 50 MHz. This setup allows for internal pro-
cessing to occur at twice the rate of on/off device I/O
transfers.
PCM Cautions
Cautions do apply when using the PCM. There are a
number of congurations that are possible in the PCM
that are theoretically valid, but may not produce viable
results. This section describes some of those situa-
tions, and should leave the user with an understanding
of the types of pitfalls that must be avoided when modi-
fying clock signals.
Resultant signals from the PCM must meet the FPGA
timing specications. It is possible to specify pulses by
using duty-cycle adjustments that are too narrow to
function in the FPGA. For instance, if a 40 MHz clock is
doubled to 80 MHz and a 6.25% duty cycle is selected,
the result will be a 780 ps pulse that repeats every
12.5 ns. This pulse falls outside of the clock pulse width
specication and is not valid.
Using divider DIV2, it is possible to specify a clock mul-
tiplication factor of 64 between the input clock and the
output system clock. As mentioned above, the resultant
frequency must meet all FPGA timing specications.
The input clock must also meet the minimum specica-
tions. An input clock rate that is below the PCM clock
minimum cannot be used even if the multiplied output is
within the allowable range.
The use of the PCM to tweak a clock signal to eliminate
a particular problem, such as a single setup time viola-
tion, is discouraged. A small shift in delay, duty cycle, or
phase to correct a single-point problem is in essence
an asynchronous patch to a synchronous system, mak-
ing the system less stable. This type of local problem,
as opposed to a global clock control issue like device-
wide clock delay, can usually be eliminated through
more robust design practices. If this type of change is
made, the designer must be aware that depending on
the extent of the change made, the design may fail to
operate correctly in a different speed grade or voltage
grade (e.g., 3C vs. 3T), or even in a different production
lot of the same device.
Divider DIV2 is available in DLL mode for the Express-
CLK
output, but its use is not recommended with duty-
cycle adjusted clocks.
Select
devices
have
been
discontinued.
See
Ordering
Information
section
for
product
status.
相关PDF资料 |
PDF描述 |
|---|---|
| OR3T307S240-DB | FPGA, 196 CLBS, 48000 GATES, PQFP240 |
| OR3T556PS240-DB | FPGA, 324 CLBS, 80000 GATES, PQFP240 |
| OR3T806PS240-DB | FPGA, 484 CLBS, 116000 GATES, PQFP240 |
| OR3T807PS240-DB | FPGA, 484 CLBS, 116000 GATES, PQFP240 |
| OR3T55-4BA256I | FPGA, 324 CLBS, 40000 GATES, 80 MHz, PBGA256 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| OR3T30-7BA256 | 制造商:AGERE 制造商全称:AGERE 功能描述:3C and 3T Field-Programmable Gate Arrays |
| OR3T307BA256-DB | 功能描述:FPGA - 现场可编程门阵列 1568 LUT 221 I/O RoHS:否 制造商:Altera Corporation 系列:Cyclone V E 栅极数量: 逻辑块数量:943 内嵌式块RAM - EBR:1956 kbit 输入/输出端数量:128 最大工作频率:800 MHz 工作电源电压:1.1 V 最大工作温度:+ 70 C 安装风格:SMD/SMT 封装 / 箱体:FBGA-256 |
| OR3T30-7BA256I | 制造商:AGERE 制造商全称:AGERE 功能描述:3C and 3T Field-Programmable Gate Arrays |
| OR3T30-7BA352 | 制造商:AGERE 制造商全称:AGERE 功能描述:3C and 3T Field-Programmable Gate Arrays |
| OR3T30-7BA352I | 制造商:AGERE 制造商全称:AGERE 功能描述:3C and 3T Field-Programmable Gate Arrays |
发布紧急采购，3分钟左右您将得到回复。