数据搜索系统,热门电子元器件搜索 |
|
LFE26E-5F672I 数据表(PDF) 40 Page - Lattice Semiconductor |
|
LFE26E-5F672I 数据表(HTML) 40 Page - Lattice Semiconductor |
40 / 386 page 2-37 Architecture Lattice Semiconductor LatticeECP2/M Family Data Sheet Figure 2-34. DQS Input Routing for the Bottom Edge of the Device DLL Calibrated DQS Delay Block Source synchronous interfaces generally require the input clock to be adjusted in order to correctly capture data at the input register. For most interfaces a PLL is used for this adjustment. However, in DDR memories the clock (referred to as DQS) is not free-running so this approach cannot be used. The DQS Delay block provides the required clock alignment for DDR memory interfaces. The DQS signal (selected PIOs only, as shown in Figure 2-35) feeds from the PAD through a DQS delay element to a dedicated DQS routing resource. The DQS signal also feeds polarity control logic, which controls the polarity of the clock to the sync registers in the input register blocks. Figure 2-35 and Figure 2-36 show how the DQS transi- tion signals are routed to the PIOs. The temperature, voltage and process variations of the DQS delay block are compensated by a set of calibration (6-bit bus) signals from two dedicated DLLs (DDR_DLL) on opposite sides of the device. Each DLL compensates DQS delays in its half of the device as shown in Figure 2-35. The DLL loop is compensated for temperature, volt- age and process variations by the system clock and feedback loop. PIO B PIO A PIO B PIO A Assigned DQS Pin DQS Delay sysIO Buffer PADA "T" PADB "C" LVDS Pair PADA "T" PADB "C" LVDS Pair PIO A PIO B PADA "T" PADB "C" LVDS Pair PIO A PIO B PADA "T" PADB "C" LVDS Pair PIO A PIO B PADA "T" PADB "C" LVDS Pair PIO A PIO B PADA "T" PADB "C" LVDS Pair PIO A PIO B PADA "T" PADB "C" LVDS Pair PIO B PIO A PADA "T" PADB "C" LVDS Pair PIO A PIO B PADA "T" PADB "C" LVDS Pair |
类似零件编号 - LFE26E-5F672I |
|
类似说明 - LFE26E-5F672I |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |