參數(shù)資料
型號: XE8807AMI026TLF
廠商: Semtech
文件頁數(shù): 83/143頁
文件大?。?/td> 0K
描述: IC MCU LOW PWR MTP FLASH 32-TQFP
標準包裝: 1
系列: XE880x
應(yīng)用: 感測機
核心處理器: Coolrisc816?
程序存儲器類型: 閃存(11 kB)
控制器系列: XE8000
RAM 容量: 512 x 8
接口: UART,USRT
輸入/輸出數(shù): 24
電源電壓: 2.4 V ~ 5.5 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 32-TQFP
包裝: 標準包裝
供應(yīng)商設(shè)備封裝: 32-TQFP(7x7)
產(chǎn)品目錄頁面: 585 (CN2011-ZH PDF)
配用: XE8000MP-ND - PROG BOARD AND PROSTART2 CARD
其它名稱: XE8807AMI026DKR
Semtech 2006
www.semtech.com
7-5
XE8806A/XE8807A
7.5
Clock sources
7.6
RC oscillator
7.6.1
Configuration
The RC oscillator is always turned on and selected for CPU and system operation at power-on reset, pad
NRESET, and when exiting sleep mode. It can be turned off after the Xtal (quartz oscillator) has been started, after
selection of the external clock or by entering sleep mode.
The RC oscillator has two frequency ranges: sub-MHz (50 kHz to 0.5 MHz) and above-MHz (0.5 MHz to 5 MHz).
Inside a range, the frequency can be tuned by software for coarse and fine adjustment. See registers
RegSysRcTrim1 and RegSysRcTrim2.
Bit EnableRc in register RegSysClock controls the propagation of the RC clock signal and the operation of the
oscillator. The user can stop the RC oscillator by resetting the bit EnableRc. Entering the sleep mode disables the
RC oscillator.
Note: The RC oscillator bias can be maintained while the oscillator is disabled by setting the bit BiasRc in
RegSysClock. This allows a faster restart of the RC oscillator at the cost of increased power consumption (see
section 7.6.3).
7.6.2
RC oscillator frequency tuning
The RC oscillator frequency can be set using the bits in the RegSysRcTrim1 and RegSysRcTrim2 registers.
Figure 7-2 shows the nominal frequency of the RC oscillator as a function of these bits. The absolute value of the
frequency for a given register content may change by
±35% from chip to chip due to the tolerances on the
integrated capacitors and resistors. However, the modification of the frequency as a function of a modification of
the register content is fairly precise. This means that the curves in Figure 7-2 can shift up and down but that the
slope remains unchanged.
The bit RcFreqRange modifies the oscillator frequency by a factor of 10. The upper curve in the figure
corresponds to RcFreqRange=1.
The RcFreqCoarse modifies the frequency of the oscillator by a factor (RcFreqCoarse+1). The figure represents
the frequency for 5 different values of the bits RcFreqCoarse: for each value the frequency is multiplied by 2.
Incrementing the RcFreqFine code, increases the frequency by about 1.4%.
The frequency of the oscillator is therefor given by:
fRC=fRcmin(1+9RcFreqRange)(1+RcFreqCoarse)(1.014)
RcFreqFine
with fRcmin the RC oscillator frequency if the registers are all 0.
相關(guān)PDF資料
PDF描述
XIO2200AGGW IC PCI-EXPRESS/BUS BRIDGE 176BGA
XIO2200AZGW IC PCI-EXPRESS/BUS BRIDGE 176BGA
XPC823ZT81B2T IC MPU POWERQUICC 81MHZ 256-PBGA
XPC8240RZU250E MCU HOST PROCESSOR 352-TBGA
XQ6SLX150T-3CSG484I IC FPGA SPARTAN-6Q 484-CSBGA
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
XE88LC01 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Sensing Machine 16 + 10 bit Data Acquisition Ultra Low-Power Microcontroller
XE88LC01MI000 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Sensing Machine 16 + 10 bit Data Acquisition Ultra Low-Power Microcontroller
XE88LC01MI027 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Sensing Machine 16 + 10 bit Data Acquisition Ultra Low-Power Microcontroller
XE88LC01MI032 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Sensing Machine 16 + 10 bit Data Acquisition Ultra Low-Power Microcontroller
XE88LC01RI000 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Sensing Machine 16 + 10 bit Data Acquisition Ultra Low-Power Microcontroller