参数资料
型号: DSP56855BUE
厂商: Freescale Semiconductor
文件页数: 17/52页
文件大小: 0K
描述: IC DSP 16BIT 120MHZ 100-LQFP
标准包装: 90
系列: 568xx
核心处理器: 56800E
芯体尺寸: 16-位
速度: 120MHz
连通性: EBI/EMI,SCI,SSI
外围设备: DMA,POR,WDT
输入/输出数: 18
程序存储器容量: 48KB(24K x 16)
程序存储器类型: SRAM
RAM 容量: 24K x 16
电压 - 电源 (Vcc/Vdd): 1.62 V ~ 1.98 V
振荡器型: 外部
工作温度: -40°C ~ 85°C
封装/外壳: 100-LQFP
包装: 托盘
56855 Technical Data, Rev. 6
24
Freescale Semiconductor
4.5 External Clock Operation
The 56855 system clock can be derived from a crystal or an external system clock signal. To generate a
reference frequency using the internal oscillator, a reference crystal must be connected between the
EXTAL and XTAL pins.
4.5.1
Crystal Oscillator
The internal oscillator is designed to interface with a parallel-resonant crystal resonator in the frequency
range specified for the external crystal in Table 4-5. In Figure 4-6 a typical crystal oscillator circuit is
shown. Follow the crystal supplier’s recommendations when selecting a crystal, because crystal
parameters determine the component values required to provide maximum stability and reliable start-up.
The crystal and associated components should be mounted as close as possible to the EXTAL and XTAL
pins to minimize output distortion and start-up stabilization time.
Figure 4-6 Crystal Oscillator
4.5.2
High Speed External Clock Source (> 4MHz)
The recommended method of connecting an external clock is given in Figure 4-7. The external clock
source is connected to XTAL and the EXTAL pin is held at ground, VDDA, or VDDA/2. The TOD_SEL
bit in CGM must be set to 0.
Figure 4-7 Connecting a High Speed External Clock Signal using XTAL
Sample External Crystal Parameters:
Rz = 10MΩ
TOD_SEL bit in CGM must be set to 0
Crystal Frequency = 2–4 MHz (optimized for 4MHz)
EXTAL XTAL
Rz
56855
XTAL
EXTAL
External
GND,
VDDA,
Clock
(up to 240MHz)
or VDDA/2
相关PDF资料
PDF描述
DSP56857BUE IC DSP 16BIT 120MHZ 100-LQFP
DSP56858FVE IC DSP 16BIT 120MHZ 144-LQFP
DSP56F801FA80E IC DSP 60MHZ 16KB FLASH 48-LQFP
DSP56F802TA80E IC DSP 60MHZ 16KB FLASH 32-LQFP
DSP56F803BU80E IC DSP 80MHZ 64KB FLASH 100LQFP
相关代理商/技术参数
参数描述
DSP56855E 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:16-bit Digital Signal Controllers
DSP56855PB 制造商:未知厂家 制造商全称:未知厂家 功能描述:56855 Digital Signal Processor Product Brief
DSP56856 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Digitial Signal Controller
DSP56857 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:16-bit Digital Signal Controllers
DSP56857BU120 功能描述:数字信号处理器和控制器 - DSP, DSC 120Mhz/120MIPS RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT