參數(shù)資料
型號(hào): MQ83C154TXXX-L16/883D
廠商: TEMIC SEMICONDUCTORS
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CQFP44
文件頁(yè)數(shù): 88/91頁(yè)
文件大?。?/td> 19688K
代理商: MQ83C154TXXX-L16/883D
46
7707F–AVR–11/10
AT90USB82/162
9.
System Control and Reset
9.1
Resetting the AVR
During reset, all I/O Registers are set to their initial values, and the program starts execution
from the Reset Vector. The instruction placed at the Reset Vector must be a JMP – Absolute
Jump – instruction to the reset handling routine. If the program never enables an interrupt
source, the Interrupt Vectors are not used, and regular program code can be placed at these
locations. This is also the case if the Reset Vector is in the Application section while the Interrupt
Vectors are in the Boot section or vice versa. The circuit diagram in Figure 9-1 shows the reset
logic. Table 9-1 defines the electrical parameters of the reset circuitry.
The I/O ports of the AVR are immediately reset to their initial state when a reset source goes
active. This does not require any clock source to be running.
After all reset sources have gone inactive, a delay counter is invoked, stretching the internal
reset. This allows the power to reach a stable level before normal operation starts. The time-out
period of the delay counter is defined by the user through the SUT and CKSEL Fuses. The dif-
ferent selections for the delay period are presented in “Clock Sources” on page 29.
9.2
Reset Sources
The AT90USB82/162 has five sources of reset:
Power-on Reset. The MCU is reset when the supply voltage is below the Power-on Reset
threshold (V
POT).
External Reset. The MCU is reset when a low level is present on the RESET pin for longer
than the minimum pulse length.
Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and the
Brown-out Reset. The MCU is reset when the supply voltage V
CC is below the Brown-out
Reset threshold (V
BOT) and the Brown-out Detector is enabled.
USB Reset. The MCU is reset when the USB macro is enabled and detects a USB Reset.
Note that with this reset the USB macro remains enabled so that the device stays attached to
the bus.
相關(guān)PDF資料
PDF描述
MQ80C154-36P883 8-BIT, 36 MHz, MICROCONTROLLER, CQFP44
S80C32E-30SHXXX:R 8-BIT, 30 MHz, MICROCONTROLLER, PQCC44
S80C52TXXX-30:RD 8-BIT, MROM, 30 MHz, MICROCONTROLLER, PQCC44
MF180C51T-20R 8-BIT, MROM, 20 MHz, MICROCONTROLLER, PQFP44
MR80C52TXXX-12/883:D 8-BIT, MROM, 12 MHz, MICROCONTROLLER, CQCC44
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MQ86 制造商:TE Connectivity 功能描述:
MQ8797BH 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Intel 功能描述:
MQ87C196KC/R 制造商:Rochester Electronics LLC 功能描述:
MQ87C196KD-16/B 制造商:Rochester Electronics LLC 功能描述:
MQ87C196KD-20/R 制造商:Rochester Electronics LLC 功能描述: