- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄25626 > MR83C154DTXXX-20/883 (ATMEL CORP) 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44 PDF資料下載
參數(shù)資料
| 型號： | MR83C154DTXXX-20/883 |
| 廠商： | ATMEL CORP |
| 元件分類： | 微控制器/微處理器 |
| 英文描述： | 8-BIT, MROM, 20 MHz, MICROCONTROLLER, CQCC44 |
| 封裝： | LCC-44 |
| 文件頁數(shù)： | 14/298頁 |
| 文件大?。?/td> | 8529K |
| 代理商： | MR83C154DTXXX-20/883 |
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頁當(dāng)前第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頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁第187頁第188頁第189頁第190頁第191頁第192頁第193頁第194頁第195頁第196頁第197頁第198頁第199頁第200頁第201頁第202頁第203頁第204頁第205頁第206頁第207頁第208頁第209頁第210頁第211頁第212頁第213頁第214頁第215頁第216頁第217頁第218頁第219頁第220頁第221頁第222頁第223頁第224頁第225頁第226頁第227頁第228頁第229頁第230頁第231頁第232頁第233頁第234頁第235頁第236頁第237頁第238頁第239頁第240頁第241頁第242頁第243頁第244頁第245頁第246頁第247頁第248頁第249頁第250頁第251頁第252頁第253頁第254頁第255頁第256頁第257頁第258頁第259頁第260頁第261頁第262頁第263頁第264頁第265頁第266頁第267頁第268頁第269頁第270頁第271頁第272頁第273頁第274頁第275頁第276頁第277頁第278頁第279頁第280頁第281頁第282頁第283頁第284頁第285頁第286頁第287頁第288頁第289頁第290頁第291頁第292頁第293頁第294頁第295頁第296頁第297頁第298頁
110
ATmega8A [DATASHEET]
8159E–AVR–02/2013
The Oscillator is optimized for use with a 32.768 kHz watch crystal. Applying an external clock to the TOSC1 pin
may result in incorrect Timer/Counter2 operation. The CPU main clock frequency must be more than four times
the Oscillator frequency.
When writing to one of the registers TCNT2, OCR2, or TCCR2, the value is transferred to a temporary register,
and latched after two positive edges on TOSC1. The user should not write a new value before the contents of
the temporary register have been transferred to its destination. Each of the three mentioned registers have their
individual temporary register, which means that e.g. writing to TCNT2 does not disturb an OCR2 write in
progress. To detect that a transfer to the destination register has taken place, the Asynchronous Status Register
– ASSR has been implemented.
When entering Power-save mode after having written to TCNT2, OCR2, or TCCR2, the user must wait until the
written register has been updated if Timer/Counter2 is used to wake up the device. Otherwise, the MCU will
enter sleep mode before the changes are effective. This is particularly important if the Output Compare2
interrupt is used to wake up the device, since the Output Compare function is disabled during writing to OCR2
or TCNT2. If the write cycle is not finished, and the MCU enters sleep mode before the OCR2UB bit returns to
zero, the device will never receive a Compare Match interrupt, and the MCU will not wake up.
If Timer/Counter2 is used to wake the device up from Power-save mode, precautions must be taken if the user
wants to re-enter one of these modes: The interrupt logic needs one TOSC1 cycle to be reset. If the time
between wake-up and re-entering sleep mode is less than one TOSC1 cycle, the interrupt will not occur, and the
device will fail to wake up. If the user is in doubt whether the time before re-entering Power-save or Extended
Standby mode is sufficient, the following algorithm can be used to ensure that one TOSC1 cycle has elapsed:
1.
Write a value to TCCR2, TCNT2, or OCR2.
2.
Wait until the corresponding Update Busy Flag in ASSR returns to zero.
3.
Enter Power-save or Extended Standby mode.
When the asynchronous operation is selected, the 32.768kHz Oscillator for Timer/Counter2 is always running,
except in Power-down and Standby modes. After a Power-up Reset or Wake-up from Power-down or Standby
mode, the user should be aware of the fact that this Oscillator might take as long as one second to stabilize. The
user is advised to wait for at least one second before using Timer/Counter2 after Power-up or Wake-up from
Power-down or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after a
wake-up from Power-down or Standby mode due to unstable clock signal upon start-up, no matter whether the
Oscillator is in use or a clock signal is applied to the TOSC1 pin.
Description of wake up from Power-save or Extended Standby mode when the timer is clocked asynchronously:
When the interrupt condition is met, the wake up process is started on the following cycle of the timer clock, that
is, the timer is always advanced by at least one before the processor can read the counter value. After wake-up,
the MCU is halted for four cycles, it executes the interrupt routine, and resumes execution from the instruction
following SLEEP.
Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect result. Since
TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be done through a register
synchronized to the internal I/O clock domain. Synchronization takes place for every rising TOSC1 edge. When
waking up from Power-save mode, and the I/O clock (clk
I/O) again becomes active, TCNT2 will read as the
previous value (before entering sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after
waking up from Power-save mode is essentially unpredictable, as it depends on the wake-up time. The
recommended procedure for reading TCNT2 is thus as follows:
1.
Write any value to either of the registers OCR2 or TCCR2.
2.
Wait for the corresponding Update Busy Flag to be cleared.
3.
Read TCNT2.
During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous timer takes
three processor cycles plus one timer cycle. The timer is therefore advanced by at least one before the
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MD83C154CXXX-25/883 | 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CDIP40 |
| MD80C52CXXX-12SCD | 8-BIT, MROM, 12 MHz, MICROCONTROLLER, CDIP40 |
| MF180C51C-25D | 8-BIT, MROM, 25 MHz, MICROCONTROLLER, PQFP44 |
| MF280C51C-36R | 8-BIT, MROM, 36 MHz, MICROCONTROLLER, PQFP44 |
| MQ80C52TXXX-16SC | 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CQFP44 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MR83C154-L16 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:CMOS 0 to 36 MHz Single Chip 8-bit Microcontroller |
| MR83C154T-12 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:CMOS 0 to 36 MHz Single Chip 8-bit Microcontroller |
| MR83C154T-16 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:CMOS 0 to 36 MHz Single Chip 8-bit Microcontroller |
| MR83C154T-20 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:CMOS 0 to 36 MHz Single Chip 8-bit Microcontroller |
| MR83C154T-25 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:CMOS 0 to 36 MHz Single Chip 8-bit Microcontroller |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。