收藏本站
参数资料
型号： ST72SCR1R4T1
厂商： 意法半导体
英文描述： 8-BIT LOW-POWER, FULL-SPEED USB MCU WITH 16K FLASH, 768 RAM, SMARTCARD I/F, TIMER
中文描述： 8位低功耗，全速USB微控制器与16K的闪存，768内存，智能卡的I /楼，计时器
文件页数： 20/102页
文件大小： 1413K
代理商： ST72SCR1R4T1
ST7SCR
20/102
1
6 SUPPLY, RESET AND CLOCK MANAGEMENT
6.1 CLOCK SYSTEM
6.1.1 General Description
The MCU accepts either a 4MHz crystal or an ex-
ternal clock signal to drive the internal oscillator.
The internal clock (f
CPU
) is derived from the inter-
nal oscillator frequency (f
OSC
), which is 4Mhz.
After reset, the internal clock (f
CPU
) is provided by
the internal oscillator (4Mhz frequency).
To activate the 48-MHz clock for the USB inter-
face, the user must turn on the PLL by setting the
PLL_ON bit in the MISCR4 register. When the PLL
is locked, the LOCK bit is set by hardware.
The user can then select an internal frequency
(f
CPU
) of either 4 MHz or 8MHz by programming
the CLK_SEL bit in the MISCR4 register (refer to
MISCELLANEOUS REGISTERS
section on
page
37
).
The PLL provides a signal with a duty cycle of 50
%.
The internal clock signal (f
CPU
) is also routed to
the on-chip peripherals. The CPU clock signal
consists of a square wave with a duty cycle of
50%.
Figure 10. Clock, Reset and Supply Block Diagram
The internal oscillator is designed to operate with
an AT-cut parallel resonant quartz in the frequen-
cy range specified for f
osc
. The circuit shown in
Figure 12
is recommended when using a crystal,
and
Table 4
lists the recommended capacitance.
The crystal and associated components should be
mounted as close as possible to the input pins in
order to minimize output distortion and start-up
stabilisation time. The LOCK bit in the MISCR4
register can also be used to generate the f
CPU
di-
rectly from f
OSC
if the PLL and the USB interface
are not active.
Table 4. Recommended Values for 4 MHz
Crystal Resonator
Note:
R
is the equivalent serial resistor of the
crystal (see crystal specification).
PLL_
ON
MISCR4
-
-
-
-
-
-
LOCK
4 Mhz
INTERNAL
8 Mhz
CLOCK (f
CPU
)
4 MHz
(f
OSC
)
PLL
X 12
48 MHz
USB
48 MHz
DIV
CLK_
SEL
R
SMAX
C
OSCIN
C
OSCOUT
20
56pF
56pF
25
47pF
47pF
70
22pF
22pF
相关PDF资料
PDF描述
ST72FSCR1R4T1 8-BIT LOW-POWER, FULL-SPEED USB MCU WITH 16K FLASH, 768 RAM, SMARTCARD I/F, TIMER
ST72PSCR1R4T1 8-BIT LOW-POWER, FULL-SPEED USB MCU WITH 16K FLASH, 768 RAM, SMARTCARD I/F, TIMER
ST72SCR1x4M1 CKTBKR
ST72FSCR1x4M1 CKTBKR
ST72PSCR1x4M1 8-BIT LOW-POWER, FULL-SPEED USB MCU WITH 16K FLASH, 768 RAM, SMARTCARD I/F, TIMER
相关代理商/技术参数
参数描述
ST72T101G1B6 功能描述:8位微控制器 -MCU OTP EPROM 4K SPI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T101G1M6 功能描述:8位微控制器 -MCU OTP EPROM 4K SPI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T101G2B6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T101G2M6 功能描述:8位微控制器 -MCU RO 511-ST72C104G2M6 RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72T121J2B6 功能描述:8位微控制器 -MCU OTP EPROM 8K SPI/SCI RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*