- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄11212 > AT91SAM7S32B-MU-999 (Atmel)IC MCU ARM7 32KB FLASH 48-VQFN PDF資料下載
參數(shù)資料
| 型號： | AT91SAM7S32B-MU-999 |
| 廠商： | Atmel |
| 文件頁數(shù)： | 156/165頁 |
| 文件大小： | 0K |
| 描述： | IC MCU ARM7 32KB FLASH 48-VQFN |
| 產(chǎn)品培訓(xùn)模塊： | MCU Product Line Introduction |
| 標(biāo)準(zhǔn)包裝： | 3,500 |
| 系列： | SAM7S |
| 核心處理器： | ARM7 |
| 芯體尺寸： | 16/32-位 |
| 速度： | 55MHz |
| 連通性： | I²C，SPI，SSC，UART/USART |
| 外圍設(shè)備： | 欠壓檢測/復(fù)位，DMA，POR，PWM，WDT |
| 輸入/輸出數(shù)： | 21 |
| 程序存儲器容量： | 32KB（32K x 8） |
| 程序存儲器類型： | 閃存 |
| RAM 容量： | 8K x 8 |
| 電壓 - 電源 (Vcc/Vdd)： | 1.65 V ~ 1.95 V |
| 數(shù)據(jù)轉(zhuǎn)換器： | A/D 8x10b |
| 振蕩器型： | 內(nèi)部 |
| 工作溫度： | -40°C ~ 85°C |
| 封裝/外殼： | 48-VFQFN 裸露焊盤 |
| 包裝： | 帶卷 (TR) |
| 配用： | AT91SAM-ICE-ND - EMULATOR FOR AT91 ARM7/ARM9 AT91SAM7S-EK-ND - KIT EVAL FOR ARM AT91SAM7S |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁當(dāng)前第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁
90
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
16.3
Functional Description
The Watchdog Timer can be used to prevent system lock-up if the software becomes trapped in a deadlock. It is
supplied with VDDCORE. It restarts with initial values on processor reset.
The Watchdog is built around a 12-bit down counter, which is loaded with the value defined in the field WDV of the
Mode Register (WDT_MR). The Watchdog Timer uses the Slow Clock divided by 128 to establish the maximum
Watchdog period to be 16 seconds (with a typical Slow Clock of 32.768 kHz).
After a Processor Reset, the value of WDV is 0xFFF, corresponding to the maximum value of the counter with the
external reset generation enabled (field WDRSTEN at 1 after a Backup Reset). This means that a default Watch-
dog is running at reset, i.e., at power-up. The user must either disable it (by setting the WDDIS bit in WDT_MR) if
he does not expect to use it or must reprogram it to meet the maximum Watchdog period the application requires.
If the watchdog is restarted by writing into WDT_CR register, the WDT_MR register must not be programmed dur-
ing a period of time of 3 slow clock period following the WDT_CR write access. In any case, programming a new
value in WDT_MR automatically initiates a restart instruction.
The Watchdog Mode Register (WDT_MR) can be written only once. Only a processor reset resets it. Writing the
WDT_MR register reloads the timer with the newly programmed mode parameters.
In normal operation, the user reloads the Watchdog at regular intervals before the timer underflow occurs, by writ-
ing the Control Register (WDT_CR) with the bit WDRSTT to 1. The Watchdog counter is then immediately
reloaded from WDT_MR and restarted, and the Slow Clock 128 divider is reset and restarted. The WDT_CR regis-
ter is write-protected. As a result, writing WDT_CR without the correct hard-coded key has no effect. If an
underflow does occur, the “wdt_fault” signal to the Reset Controller is asserted if the bit WDRSTEN is set in the
Mode Register (WDT_MR). Moreover, the bit WDUNF is set in the Watchdog Status Register (WDT_SR).
To prevent a software deadlock that continuously triggers the Watchdog, the reload of the Watchdog must occur
while the Watchdog counter is within a window between 0 and WDD, WDD is defined in the WatchDog Mode Reg-
ister WDT_MR.
Any attempt to restart the Watchdog while the Watchdog counter is between WDV and WDD results in a Watchdog
error, even if the Watchdog is disabled. The bit WDERR is updated in the WDT_SR and the “wdt_fault” signal to
the Reset Controller is asserted.
Note that this feature can be disabled by programming a WDD value greater than or equal to the WDV value. In
such a configuration, restarting the Watchdog Timer is permitted in the whole range [0; WDV] and does not gener-
ate an error. This is the default configuration on reset (the WDD and WDV values are equal).
The status bits WDUNF (Watchdog Underflow) and WDERR (Watchdog Error) trigger an interrupt, provided the bit
WDFIEN is set in the mode register. The signal “wdt_fault” to the reset controller causes a Watchdog reset if the
WDRSTEN bit is set as already explained in the reset controller programmer Datasheet. In that case, the proces-
sor and the Watchdog Timer are reset, and the WDERR and WDUNF flags are reset.
If a reset is generated or if WDT_SR is read, the status bits are reset, the interrupt is cleared, and the “wdt_fault”
signal to the reset controller is deasserted.
Writing the WDT_MR reloads and restarts the down counter.
While the processor is in debug state or in idle mode, the counter may be stopped depending on the value pro-
grammed for the bits WDIDLEHLT and WDDBGHLT in the WDT_MR.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ATMEGA165P-16MNR | IC MCU AVR 16K 16MHZ 64MLF |
| ATMEGA16U2-MU | MCU AVR 16K FLASH USB 32VQFN |
| VI-B2K-IW-F3 | CONVERTER MOD DC/DC 40V 100W |
| VI-B2J-IX-F2 | CONVERTER MOD DC/DC 36V 75W |
| VI-B2J-IW-F4 | CONVERTER MOD DC/DC 36V 100W |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AT91SAM7S32-MU | 功能描述:ARM微控制器 - MCU QFN IND TEMP RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 處理器系列:STM32F373xx 數(shù)據(jù)總線寬度:32 bit 最大時(shí)鐘頻率:72 MHz 程序存儲器大小:256 KB 數(shù)據(jù) RAM 大小:32 KB 片上 ADC:Yes 工作電源電壓:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:LQFP-48 安裝風(fēng)格:SMD/SMT |
| AT91SAM7S32-MU-999 | 功能描述:ARM微控制器 - MCU Microcontroller RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 處理器系列:STM32F373xx 數(shù)據(jù)總線寬度:32 bit 最大時(shí)鐘頻率:72 MHz 程序存儲器大小:256 KB 數(shù)據(jù) RAM 大小:32 KB 片上 ADC:Yes 工作電源電壓:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:LQFP-48 安裝風(fēng)格:SMD/SMT |
| AT91SAM7S512 | 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:AT91 ARM Thumb-based Microcontrollers |
| AT91SAM7S512-AU | 功能描述:ARM微控制器 - MCU LQFP IND TEMP RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 處理器系列:STM32F373xx 數(shù)據(jù)總線寬度:32 bit 最大時(shí)鐘頻率:72 MHz 程序存儲器大小:256 KB 數(shù)據(jù) RAM 大小:32 KB 片上 ADC:Yes 工作電源電壓:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:LQFP-48 安裝風(fēng)格:SMD/SMT |
| AT91SAM7S512-AU-999 | 功能描述:ARM微控制器 - MCU Ind. Temp Green RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 處理器系列:STM32F373xx 數(shù)據(jù)總線寬度:32 bit 最大時(shí)鐘頻率:72 MHz 程序存儲器大小:256 KB 數(shù)據(jù) RAM 大小:32 KB 片上 ADC:Yes 工作電源電壓:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:LQFP-48 安裝風(fēng)格:SMD/SMT |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。