參數(shù)資料
型號(hào)： DS80C320-ENL
廠商： DALLAS SEMICONDUCTOR
元件分類： Microcontroller
英文描述： 8-BIT, MROM, 33 MHz, MICROCONTROLLER, PQFP44
封裝： TQFP-44
文件頁(yè)數(shù)： 6/42頁(yè)
文件大?。?/td> 736K
代理商： DS80C320-ENL
DS80C320/DS80C323
14 of 42
POWER-FAIL RESET
The DS80C320/DS80C323 incorporates a precision band-gap voltage reference to determine when VCC is
out of tolerance. While powering up, internal circuits will hold the device in a reset state until VCC rises
above the VRST reset threshold. Once VCC is above this level, the oscillator will begin running. An internal
reset circuit will then count 65536 clocks to allow time for power and the oscillator to stabilize. The
microcontroller will then exit the reset condition. No external components are needed to generate a power
on reset. During power-down or during a severe power glitch, as VCC falls below VRST, the
microcontroller will also generate its own reset. It will hold the reset condition as long as power remains
below the threshold. This reset will occur automatically, needing no action from the user or from the
software. Refer to the Electrical Specifications for the exact value of VRST.
POWER-FAIL INTERRUPT
The same reference that generates a precision reset threshold can also generate an optional early warning
Power-fail Interrupt (PFI). When enabled by the application software, this interrupt always has the
highest priority. On detecting that the VCC has dropped below VPFW and that the PFI is enabled, the
processor will vector to ROM address 0033h. The PFI enable is located in the Watchdog Control SFR
(WDCON - D8h). Setting WDCON.5 to a logic 1 will enable the PFI. The application software can also
read a flag at WDCON.4. This bit is set when a PFI condition has occurred. The flag is independent of
the interrupt enable and software must manually clear it.
WATCHDOG TIMER
For applications that can not afford to run out of control, the DS80C320/DS80C323 incorporates a
programmable watchdog timer circuit. It resets the microcontroller if software fails to reset the watchdog
before the selected time interval has elapsed. The user selects one of four timeout values. After enabling
the watchdog, software must reset the timer prior to expiration of the interval, or the CPU will be reset.
Both the Watchdog Enable and the Watchdog Reset bits are protected by a “Timed Access” circuit. This
prevents accidentally clearing the watchdog. Timeout values are precise since they are related to the
crystal frequency as shown below in Table 4. For reference, the time periods at 25 MHz are also shown.
The watchdog timer also provides a useful option for systems that may not require a reset. If enabled,
then 512 clocks before giving a reset, the watchdog will give an interrupt. The interrupt can also serve as
a convenient time-base generator, or be used to wake-up the processor from Idle mode. The watchdog
function is controlled in the Clock Control (CKCON - 8Eh), Watchdog Control (WDCON - D8h), and
Extended Interrupt Enable (EIE - E8h) SFRs. CKCON.7 and CKCON.6 are called WD1 and WD0
respectively and are used to select the watchdog timeout period as shown in Table 4.
WATCHDOG TIMEOUT VALUES Table 4
INTERRUPT
TIME
RESET
TIME
WD1
WD0
TIMEOUT
(@25 MHz)
TIMEOUT
(@25 MHz)
00
217 clocks
5.243 ms
217 + 512 clocks
5.263 ms
j
01
220 clocks
41.94 ms
220 + 512 clocks
41.96 ms
10
223 clocks
335.54 ms
223 + 512 clocks
335.56 ms
11
226 clocks
2684.35 ms
226 + 512 clocks
2684.38 ms
As shown above, the watchdog timer uses the crystal frequency as a time base. A user selects one of four
counter values to determine the timeout. These clock counter lengths are 217 = 131,072 clocks; 220=
1,048,576; 223= 8,388,608 clocks; or 226= 67,108,864 clocks. The times shown in Table 4 are with a 25
相關(guān)PDF資料
PDF描述
DS80C320-ENG 8-BIT, MROM, 25 MHz, MICROCONTROLLER, PQFP44
DS80C320-MCG 8-BIT, MROM, 25 MHz, MICROCONTROLLER, PDIP40
DS80C320-QNG 8-BIT, MROM, 25 MHz, MICROCONTROLLER, PQCC44
DS80C320-ECG 8-BIT, MROM, 25 MHz, MICROCONTROLLER, PQFP44
DS80C320-FNG 8-BIT, 25 MHz, MICROCONTROLLER, PQFP44
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS80C320-ENL+ 功能描述:8位微控制器 -MCU High-Speed Low-Power RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
DS80C320-ENR 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:High-Speed Microcontroller User Guide
DS80C320-FCD 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:High-Speed Microcontroller User Guide
DS80C320-FCG 功能描述:8位微控制器 -MCU High-Speed Low-Power RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
DS80C320-FCG+ 功能描述:8位微控制器 -MCU High-Speed Low-Power RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*