參數(shù)資料
型號: DS87C520-ENL
英文描述: EPROM/ROM High-Speed Micro
中文描述: 存儲器/ ROM的高速微
文件頁數(shù): 24/45頁
文件大?。?/td> 1415K
代理商: DS87C520-ENL
DS87C520/DS83C520 EPROM/ROM High-Speed Microcontrollers
24 of 45
will set an interrupt flag. Regardless of whether the user enables this interrupt, there are then 512 clocks
left until the reset flag is set. Software can enable the interrupt and reset individually. Note that the
Watchdog is a free running timer and does not require an enable.
There are 5 control bits in special function registers that affect the Watchdog Timer and two status flags
that report to the user. WDIF (WDCON.3) is the interrupt flag that is set at timer termination when there
are 512 clocks remaining until the reset flag is set. WTRF (WDCON.2) is the flag that is set when the
timer has completely timed out. This flag is normally associated with a CPU reset and allows software to
determine the reset source.
EWT (WDCON.1) is the enable for the Watchdog timer reset function. RWT (WDCON.0) is the bit that
software uses to restart the Watchdog Timer. Setting this bit restarts the timer for another full interval.
Application software must set this bit before the timeout. Both of these bits are protected by Timed
Access. As mentioned previously, WD1 and 0 (CKCON .7 and 6) select the timeout. The Reset
Watchdog Timer bit (WDCON.0) should be asserted prior to modifying the Watchdog Timer Mode
Select bits (WD1, WD0) to avoid corruption of the watchdog count. Finally, the user can enable the
Watchdog Interrupt using EWDI (EIE.4). The Special Function Register map is shown above.
INTERRUPTS
The DS87C520/DS83C520 provide 13 interrupt sources with three priority levels. The Power-Fail
Interrupt (PFI) has the highest priority. Software can assign high or low priority to other sources. All
interrupts that are new to the 8051 family, except for the PFI, have a lower natural priority than the
originals.
Table 8. Interrupt Sources and Priorities
NAME
FUNCTION
VECTOR
NATURAL
PRIORITY
1
8051/DALLAS
PFI
Power-Fail Interrupt
33h
DALLAS
INT0
TF0
External Interrupt 0
03h
2
8051
Timer 0
0Bh
3
8051
INT1
TF1
SCON0
TF2
SCON1
INT2
External Interrupt 1
13h
4
8051
Timer 1
TI0 or RI0 from serial port 0
Timer 2
TI1 or RI1 from serial port 1
External Interrupt 2
1Bh
23h
2Bh
3Bh
43h
5
6
7
8
9
8051
8051
8051
DALLAS
DALLAS
INT3
INT4
External Interrupt 3
4Bh
10
DALLAS
External Interrupt 4
53h
11
DALLAS
INT5
WDTI
External Interrupt 5
5Bh
12
DALLAS
Watchdog Timeout Interrupt
63h
13
DALLAS
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS87C520-ENL+ 功能描述:8位微控制器 -MCU EPROM/ROM High-Speed 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 最大時鐘頻率:50 MHz 程序存儲器大小: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
DS87C520-FCL 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller
DS87C520MCL 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:EPROM/ROM High-Speed Microcontrollers
DS87C520-MCL 功能描述:8位微控制器 -MCU EPROM/ROM High-Speed 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 最大時鐘頻率:50 MHz 程序存儲器大小: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
DS87C520-MCL+ 功能描述:8位微控制器 -MCU EPROM/ROM High-Speed 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 最大時鐘頻率:50 MHz 程序存儲器大小: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