- 您现在的位置：买卖IC网 > PDF目录33779 > 440EPX (Applied Micro Circuits Corp.) PowerPC 440EPx Embedded Processor PDF资料下载
参数资料
| 型号： | 440EPX |
| 厂商： | Applied Micro Circuits Corp. |
| 英文描述： | PowerPC 440EPx Embedded Processor |
| 中文描述： | 嵌入式处理器的PowerPC 440EPx |
| 文件页数： | 84/94页 |
| 文件大小： | 738K |
| 代理商： | 440EPX |
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页当前第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
440EPx – PPC440EPx Embedded Processor
Revision 1.26 – October 15, 2007
AMCC Proprietary
85
Preliminary Data Sheet
DDR2/1 SDRAM I/O Specifications
The DDR2/1 SDRAM controller times its operation using the internal PLB clock signal and generates MemClkOut
from the PLB clock. The PLB clock is an internal signal that cannot be directly observed. However, MemClkOut is
the same frequency as the PLB clock signal and is in phase with the PLB clock signal. The phase skew between
MemClkOut and the PLB clock is affected by the loading on MemClkOut.
Read capture logic in the DDR controller captures read data using a delayed version of DQS and internally re-
synchronizes the data to the PLB clock.The PPC440EPx contains three independently programmable digital delay
lines (DLLs) that control the timing of the indicated signals in read and write operations:
1. DQS (with respect to MemClkOut) for write operations.
2. MemData, ECC, and DM (with respect to MemClkOut) for write operations.
3. DQS (with respect to inbound MemData) for read operations.
There is also a master delay line for calibration. Programming details can be found in the PPC440EPx Embedded
Processor Users Manual.
The signals are terminated as indicated in Figure 10 for the DDR timing data in the following sections.
The PPC440EPx uses a clock forwarding scheme in which it drives the clock to the memory devices.
Data signals are divided into eight subgroups—one for each byte lane (see Table 26 on page 89)— plus a ninth
subgroup for the ECC byte lane. These signals include MemData00:63, DQS0:8, DM0:8, and ECC0:7 signals.
Signals within a data subgroup (byte lane) should be routed together.
Command Bus Operation
The command bus (MemAddr, RAS, CAS, WE, BA, ClkEn, BankSel, MemODT) is driven 180
° out-of-phase with
MemClkOut, and has no corresponding delay line. Therefore, board designers must consider two different types of
systems: 1) registered DIMMs and 2) unbuffered DIMMs. The system clocking design must also be considered. To
avoid crosstalk, the command bus signals and the data signals should not be routed together.
Board Layout Restrictions
The paths (traces) for the data and the associated data strobe signal should be routed with the same length
between the PPC440EPx and the SDRAM devices, allowing the rising and falling edges of the strobe to arrive at
the capture logic at the same time the data is in transition. All of the following timing assumes a trace velocity of
167ps/in.
Board designs must meet the following criteria:
Skew on the signals in any byte lane should not exceed 50 ps (0.3 in).
Data subgroup trace lengths must be no more than 5in. (800ps) and have a difference of no more than 2.5in.
(400ps).
Byte lane subgroup trace length must be no less than 1.25 in. (209 ps).
For example, traces that average 3.00in. in length and 167ps/in., and meet the maximum 50ps skew requirement,
would have a maximum length difference of 0.3in. So, they would be between 2.85in. and 3.15in. in length.
If the above timing recommendations are followed, the package wire bond lengths can be ignored.
Clocking
Clocking skew to all DRAMs must be minimized. The maximum allowed is considered to be 10ps. Because of the
stringent requirements on DDR device clock inputs, it is expected that board designers will use some type of
external PLL suitable to redrive the clock to the DDR SDRAMs. In such a system, the PLL acts like a zero-delay
相关PDF资料 |
PDF描述 |
|---|---|
| 440EP | Power PC 440EP Embedded Processor |
| 440GP | Power PC 440GP Embedded Processor |
| 440GRX | PowerPC 440GRx Embedded Processor |
| 440GR | Power PC 440GR Embedded Processor |
| 440GX | Power PC 440GX Embedded Processor |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 440ES001B1434-4 | 功能描述:环形MIL规格后盖 CRIMIP RING ADPTR DC STRAIGHT RoHS:否 制造商:Amphenol PCD MIL 类型:MIL-DTL-38999 III, IV 系列:AS85049 产品类型:Environmental EMI/RFI Backshells 外壳类型:Straight 外壳大小:18 外壳材质:Aluminum Alloy |
| 440ES031M1633-3B | 功能描述:环形MIL规格后盖 BND/SHRNK BOOT ADPTR DC STRAIGHT BAND RoHS:否 制造商:Amphenol PCD MIL 类型:MIL-DTL-38999 III, IV 系列:AS85049 产品类型:Environmental EMI/RFI Backshells 外壳类型:Straight 外壳大小:18 外壳材质:Aluminum Alloy |
| 440ES031M2003-3B | 功能描述:环形MIL规格后盖 BND/SHRNK BOOT ADPTR DC STRAIGHT BAND RoHS:否 制造商:Amphenol PCD MIL 类型:MIL-DTL-38999 III, IV 系列:AS85049 产品类型:Environmental EMI/RFI Backshells 外壳类型:Straight 外壳大小:18 外壳材质:Aluminum Alloy |
| 440FA002NF1002-N | 功能描述:环形MIL规格后盖 RoHS:否 制造商:Amphenol PCD MIL 类型:MIL-DTL-38999 III, IV 系列:AS85049 产品类型:Environmental EMI/RFI Backshells 外壳类型:Straight 外壳大小:18 外壳材质:Aluminum Alloy |
| 440FA002NF1006-N | 功能描述:环形MIL规格后盖 RoHS:否 制造商:Amphenol PCD MIL 类型:MIL-DTL-38999 III, IV 系列:AS85049 产品类型:Environmental EMI/RFI Backshells 外壳类型:Straight 外壳大小:18 外壳材质:Aluminum Alloy |
发布紧急采购，3分钟左右您将得到回复。