参数资料
型号: MPC8272ADS
厂商: Freescale Semiconductor
文件页数: 58/158页
文件大小: 0K
描述: KIT DEVELOPMENT MPC8272
标准包装: 1
类型: MPU
适用于相关产品: MPC8272
所含物品:
Bus Configuration
Low Skew Clock Buffer
CLOCK GEN.
100 MHZ
MPC8272
DLLOUT
CLKIN1
CLKIN2
IN
OUT4
OUT1
OUT2
OUT3
PCI Device
#1
PCI Device
#2
PCI Device
#3
Figure 5-4. PCI Clock Generator Scheme
5.3
Bus Configuration
The MPC8272on the board is configured in one possible bus mode, which is single
MPC8272 mode.
5.3.1
Single PowerQUICC II Mode
The MPC8272 is configured in single MPC8272 mode, assuming only one MPC8272 on
the 60x bus with no support for external master access. This configuration allows for
internal address multiplexing to occur, which makes external address multiplexers
redundant and unused, improving SDRAM performance.
5.4
Buffering
To achieve optimal performance, it is necessary to reduce the capacitive load over the 60X
bus as much as possible. The slower devices on the bus, that is, the Flash SIMM, E 2 PROM,
ATM UNI M/P interface, PCI interrupt controller and the BCSR are buffered, while the
SDRAM is not buffered from the 60X bus.
Latches are provided over address and strobe (when necessary) lines while transceivers are
provided for data. Use is done with 74ALVT buffers (by Philips) which are 3.3 V operated
and 5-V tolerant 1 , and provide bus hold to reduce pull-up/pull-down resistors count (as the
MPC8272 requires). This type of buffer reduces noise on board due to reduced transition
amplitude.
To reduce noise and reflections further, serial damping resistors are placed over SDRAM
address and all MPC8272 strobe lines.
The data transceivers are open only if there is an access to a valid 2 buffered board address
or during hard reset configuration 3 . Data conflicts are avoided in case an unbuffered
1 Required
for Flash, E 2 PROM, Interrupt Controller and BCSR
2 An
address which is covered in a Chip-Select region, that controls a buffered device.
3 To allow a configuration word stored in the Flash/E 2 PROM memory to become active.
MPC8272ADS User Guide
相关PDF资料
PDF描述
MPC8308-RDB BOARD REF DESIGN MPC8308
MPC8309-KIT KIT EVALUATION FOR MPC830X
MPC8315E-RDB PROCESSOR BOARD PWRQUICCII PBGA
MPC8349E-MITX-GP KIT REFERENCE PLATFORM MPC8349E
MPC8349E-MITXE BOARD REFERENCE FOR MPC8349
相关代理商/技术参数
参数描述
MPC8272CVR 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:MPC8272 PowerQUICC II Family Hardware Specifications
MPC8272CVRB 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:PowerQUICC II⑩ Family Hardware Specifications
MPC8272CVRE 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:PowerQUICC II⑩ Family Hardware Specifications
MPC8272CVRI 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:PowerQUICC II⑩ Family Hardware Specifications
MPC8272CVRM 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:PowerQUICC II⑩ Family Hardware Specifications