- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄69016 > M41T94MQ6TR (STMICROELECTRONICS) 1 TIMER(S), REAL TIME CLOCK, PDSO16 PDF資料下載
參數(shù)資料
| 型號： | M41T94MQ6TR |
| 廠商： | STMICROELECTRONICS |
| 元件分類： | 時鐘/數(shù)據(jù)恢復(fù)及定時提取 |
| 英文描述： | 1 TIMER(S), REAL TIME CLOCK, PDSO16 |
| 封裝： | PLASTIC, SOIC-16 |
| 文件頁數(shù)： | 15/40頁 |
| 文件大小： | 328K |
| 代理商： | M41T94MQ6TR |
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頁當(dāng)前第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
Clock operations
M41T94
4.4
Watchdog timer
The watchdog timer can be used to detect an out-of-control microprocessor. The user
programs the watchdog timer by setting the desired amount of time-out into the Watchdog
register, address 09h. bits BMB4-BMB0 store a binary multiplier and the two lower order bits
RB1-RB0 select the resolution, where 00 = 1/16 second, 01 =
1/
4 second, 10 = 1 second,
and 11 = 4 seconds. The amount of time-out is then determined to be the multiplication of
the five-bit multiplier value with the resolution. (For example: writing 00001110 in the
Watchdog register = 3*1 or 3 seconds).
Note:
Accuracy of timer is within ± the selected resolution.
If the processor does not reset the timer within the specified period, the M41T94 sets the
WDF (Watchdog Flag) and generates a watchdog interrupt or a microprocessor reset. WDF
is reset by reading the Flags register (0Fh).
The most significant bit of the Watchdog register is the Watchdog Steering bit (WDS). When
set to a '0,' the watchdog will activate the IRQ/FT/OUT pin when timed-out. When WDS is
set to a '1,' the watchdog will output a negative pulse on the RST pin for tREC. The Watchdog
register and the AFE, ABE, SQWE, and FT bits will reset to a '0' at the end of a Watchdog
time-out when the WDS bit is set to a '1.'
The watchdog timer can be reset by two methods:
1.
a transition (high-to-low or low-to-high) can be applied to the Watchdog Input pin (WDI),
or
2.
the microprocessor can perform a WRITE of the Watchdog register.
The time-out period then starts over. The WDI pin should be tied to VSS if not used. In order
to perform a software reset of the watchdog timer, the original time-out period can be written
into the Watchdog register, effectively restarting the count-down cycle.
Should the watchdog timer time-out, and the WDS bit is programmed to output an interrupt,
a value of 00h needs to be written to the Watchdog register in order to clear the
IRQ/FT/OUT pin. This will also disable the watchdog function until it is again programmed
correctly. A READ of the Flags register will reset the Watchdog Flag (bit D7; register 0Fh).
The watchdog function is automatically disabled upon power-up and the Watchdog register
is cleared. If the watchdog function is set to output to the IRQ/FT/OUT pin and the
Frequency Test (FT) function is activated, the watchdog function prevails and the Frequency
Test function is denied.
4.5
Square Wave output
The M41T94 offers the user a programmable Square Wave function which is output on the
SQW pin. RS3-RS0 bits located in 13h establish the Square Wave output frequency. These
frequencies are listed in Table Table 6 on page 23. Once the selection of the SQW
frequency has been completed, the SQW pin can be turned on and off under software
control with the Square Wave Enable bit (SQWE) located in register 0Ah.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| M44C092-H | 4-BIT, MROM, 4 MHz, MICROCONTROLLER, PDSO20 |
| M44C892-H | 4-BIT, MROM, 4 MHz, MICROCONTROLLER, PDSO20 |
| M44C092-V | 4-BIT, MROM, 4 MHz, MICROCONTROLLER, PDSO20 |
| M48T02-120PC1 | 0 TIMER(S), REAL TIME CLOCK, PDIP24 |
| M48T08Y-15MH1E | REAL TIME CLOCK, PDSO28 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| M41T94SH | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:512 Bit 64 bit x8 SERIAL RTC SPI SRAM |
| M41TC8025 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Highly accurate, temperature-compensated serial real-time clock (RTC) with embedded crystal |
| M41TC8025AMC6F | 制造商:STMicroelectronics 功能描述:Real Time Clock Serial 14-Pin SOIC T/R 制造商:STMicroelectronics 功能描述:HIGH-END SENSOR AND ANALOG - Tape and Reel 制造商:STMicroelectronics 功能描述:HIGH-END SENSOR and ANALOG |
| M41TC8025CMC7F | 制造商:STMicroelectronics 功能描述:HIGHLY ACCURATE, TEMPERATURE-COMPENSATEDSERIAL REAL-TIME CL - Tape and Reel |
| M41TM6 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:512 bit 64b x8 Serial Access TIMEKEEPER SRAM |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。