参数资料
型号: ST72652AR4T1/XXX
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, MICROCONTROLLER, PQFP64
封装: 10 X 10 MM, ROHS COMPLIANT, TQFP-64
文件页数: 83/161页
文件大小: 2656K
代理商: ST72652AR4T1/XXX
ST72651AR6
28/161
Doc ID 7215 Rev 4
RESET SEQUENCE MANAGER (Cont’d)
6.2.2 Asynchronous External RESET pin
The RESET pin is both an input and an open-drain
output with integrated RON weak pull-up resistor.
This pull-up has no fixed value but varies in ac-
cordance with the input voltage. It can be pulled
low by external circuitry to reset the device. See
electrical characteristics section for more details.
A RESET signal originating from an external
source must have a duration of at least th(RSTL)in in
order to be recognized. This detection is asynchro-
nous and therefore the MCU can enter reset state
even in HALT mode.
The RESET pin is an asynchronous signal which
plays a major role in EMS performance. In a noisy
environment, it is recommended to follow the
guidelines mentioned in the electrical characteris-
tics section.
If the external RESET pulse is shorter than
tw(RSTL)out (see short ext. Reset in Figure 17), the
signal on the RESET pin will be stretched. Other-
wise the delay will not be applied (see long ext.
Reset in Figure 17).
Starting from the external RESET pulse recogni-
tion, the device RESET pin acts as an output that
is pulled low during at least tw(RSTL)out.
6.2.3 Internal Low Voltage Detection RESET
Two different RESET sequences caused by the in-
ternal LVD circuitry can be distinguished:
Power-On RESET
Voltage Drop RESET
The device RESET pin acts as an output that is
pulled low when VDD<VIT+ (rising edge) or
VDD<VIT- (falling edge) as shown in Figure 17.
The LVD filters spikes on VDD shorter than tg(VDD)
to avoid parasitic resets.
6.2.4 Internal Watchdog RESET
The RESET sequence generated by a internal
Watchdog counter overflow is shown in Figure 17.
Starting from the Watchdog counter underflow, the
device RESET pin acts as an output that is pulled
low during at least tw(RSTL)out.
Figure 18. Reset Block Diagram
fCPU
CO
UN
TER
RESET
RON
VDD
WATCHDOG RESET
LVD RESET
INTERNAL
RESET
PULSE
GENERATOR
1
相关PDF资料
PDF描述
ST72651AR6T1E/XXX 8-BIT, MROM, MICROCONTROLLER, PQFP64
ST72652C4T1/XXX 8-BIT, MROM, MICROCONTROLLER, PQFP48
ST7267R8T1L/XXX 16-BIT, MROM, 30 MHz, RISC MICROCONTROLLER, PQFP64
ST7267C8T1/XXX 16-BIT, MROM, 30 MHz, RISC MICROCONTROLLER, PQFP48
ST72774S9T1/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP44
相关代理商/技术参数
参数描述
ST7265X-EVAL/MS 制造商:STMicroelectronics 功能描述:ST6 EVAL BD - Bulk
ST7265X-EVAL/PFD 制造商:STMicroelectronics 功能描述:USB FLASH EVAL - Bulk
ST7266 制造商:6940 功能描述:ST7266
ST7267C8T1L 制造商:STMicroelectronics 功能描述:
ST72681/R12 制造商:STMicroelectronics 功能描述:CONTROLLER FOR HIGH-PERFORMANCE BUS-POWERED USB 2.0 FLASH DR - Trays