参数资料
型号: MPC8308-KIT
厂商: Freescale Semiconductor
文件页数: 70/83页
文件大小: 0K
描述: KIT EVALUATION FOR MPC830X
标准包装: 1
系列: PowerQUICC II™ PRO
类型: MPU
适用于相关产品: MPC8308
所含物品: 板,线缆,CD,电源
MPC8308 PowerQUICC II Pro Processor Hardware Specification, Rev. 3
72
Freescale Semiconductor
Clocking
21.1
System Clock Domains
The primary clock input (SYS_CLK_IN) frequency is multiplied up by the system phase-locked loop
(PLL) and the clock unit to create three major clock domains:
The coherent system bus clock (csb_clk)
The internal clock for the DDR controller (ddr_clk)
The internal clock for the local bus interface unit (lbc_clk)
The csb_clk frequency is derived as follows:
csb_clk = [SYS_CLK_IN] × SPMF
The csb_clk serves as the clock input to the e300 core. A second PLL inside the core multiplies up the
csb_clk frequency to create the internal clock for the core (core_clk). The system and core PLL multipliers
are selected by the SPMF and COREPLL fields in the reset configuration word low (RCWL), which is
loaded at power-on reset or by one of the hard-coded reset options. For more information, see the Reset
Clock Configuration chapter in the MPC8308 PowerQUICC II Pro Processor Reference Manual.
The DDR SDRAM memory controller will operate with a frequency equal to twice the frequency of
csb_clk. Note that ddr_clk is not the external memory bus frequency; ddr_clk passes through the DDR
clock divider (
2) to create the differential DDR memory bus clock outputs (MCK and MCK). However,
the data rate is the same frequency as ddr_clk.
The local bus memory controller will operate with a frequency equal to the frequency of csb_clk. Note that
lbc_clk is not the external local bus frequency; lbc_clk passes through the LBC clock divider to create the
external local bus clock outputs (LSYNC_OUT and LCLK0:2). The LBC clock divider ratio is controlled
by LCCR[CLKDIV]. For more information, see the Reset Clock Configuration chapter in the MPC8308
PowerQUICC II Pro Processor Reference Manual.
In addition, some of the internal units may be required to be shut off or operate at lower frequency than
the csb_clk frequency. These units have a default clock ratio that can be configured by a memory mapped
register after the device comes out of reset. Table 54 specifies which units have a configurable clock
frequency. For more information, see Reset Clock Configuration chapter in the MPC8308 PowerQUICC
II Pro Processor Reference Manual.
NOTE
The clock ratios of these units must be set before they are accessed.
Table 54. Configurable Clock Units
Unit
Default Frequency
Options
eTSEC1,eTSEC2
csb_clk/3
Off, csb_clk, csb_clk/2, csb_clk/3
I2C
csb_clk
Off, csb_clk,csb_clk/2, csb_clk/3
DMA complex
csb_clk
Off, csb_clk,csb_clk/2,csb_clk/3
PCIEXP
csb_clk
Off, csb_clk
eSDHC
csb_clk
Off, csb_clk, csb_clk/2, csb_clk/3
USB
csb_clk
Off, csb_clk, csb_clk/2, csb_clk/3
相关PDF资料
PDF描述
EBA22DTMH CONN EDGECARD 44POS R/A .125 SLD
EBA22DTMD CONN EDGECARD 44POS R/A .125 SLD
EBM36DCSN CONN EDGECARD 72POS DIP .156 SLD
EBA22DTBN CONN EDGECARD 44POS R/A .125 SLD
EBM36DCSH CONN EDGECARD 72POS DIP .156 SLD
相关代理商/技术参数
参数描述
MPC8308-NSG 功能描述:开发板和工具包 - 其他处理器 MPC8308-NSG RoHS:否 制造商:Freescale Semiconductor 产品:Development Systems 工具用于评估:P3041 核心:e500mc 接口类型:I2C, SPI, USB 工作电源电压:
MPC8308-NSG 制造商:Freescale Semiconductor 功能描述:MPC8308-NSG*NIC*
MPC8308-RDB 功能描述:开发板和工具包 - 其他处理器 Refer. Board MPC8308 RoHS:否 制造商:Freescale Semiconductor 产品:Development Systems 工具用于评估:P3041 核心:e500mc 接口类型:I2C, SPI, USB 工作电源电压:
MPC8308-RDB-PROMO 制造商:Freescale 功能描述:Motherboards MPC8308 PowerQuicc II DDR2 10Mbps/100Mbps/1000Mbps Linux Kernel
MPC8308-SOM 功能描述:开发板和工具包 - 其他处理器 For MPC8308 Ethernet USB 32bit RoHS:否 制造商:Freescale Semiconductor 产品:Development Systems 工具用于评估:P3041 核心:e500mc 接口类型:I2C, SPI, USB 工作电源电压: