- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄368730 > 16F84A (Microchip Technology Inc.) CAT 5E CROSSOVER PATCH CORD CABLE BLUE 20 FT PDF資料下載
參數(shù)資料
| 型號(hào)： | 16F84A |
| 廠商： | Microchip Technology Inc. |
| 英文描述： | CAT 5E CROSSOVER PATCH CORD CABLE BLUE 20 FT |
| 中文描述： | 18引腳閃存/ EEPROM的8位微控制器 |
| 文件頁(yè)數(shù)： | 29/124頁(yè) |
| 文件大?。?/td> | 1322K |
| 代理商： | 16F84A |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)當(dāng)前第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)
PIC16F8X
1998 Microchip Technology Inc.
DS30430C-page 29
6.2
Using TMR0 with External Clock
When an external clock input is used for TMR0, it must
meet certain requirements. The external clock
requirement is due to internal phase clock (T
OSC
)
synchronization. Also, there is a delay in the actual
incrementing
of
the
synchronization.
TMR0
register
after
6.2.1
EXTERNAL CLOCK SYNCHRONIZATION
When no prescaler is used, the external clock input is
the same as the prescaler output. The synchronization
of pin RA4/T0CKI with the internal phase clocks is
accomplished by sampling the prescaler output on the
Q2 and Q4 cycles of the internal phase clocks
(Figure 6-5). Therefore, it is necessary for T0CKI to be
high for at least 2Tosc (plus a small RC delay) and low
for at least 2Tosc (plus a small RC delay). Refer to the
electrical specification of the desired device.
When a prescaler is used, the external clock input is
divided by an asynchronous ripple counter type
prescaler so that the prescaler output is symmetrical.
For the external clock to meet the sampling
requirement, the ripple counter must be taken into
account. Therefore, it is necessary for T0CKI to have a
period of at least 4Tosc (plus a small RC delay) divided
by the prescaler value. The only requirement on T0CKI
high and low time is that they do not violate the
minimum pulse width requirement of 10 ns. Refer to
parameters 40, 41 and 42 in the AC Electrical
Specifications of the desired device.
6.2.2
TMR0 INCREMENT DELAY
Since the prescaler output is synchronized with the
internal clocks, there is a small delay from the time the
external clock edge occurs to the time the Timer0
Module is actually incremented. Figure 6-5 shows the
delay from the external clock edge to the timer
incrementing.
6.3
Prescaler
An 8-bit counter is available as a prescaler for the
Timer0 Module, or as a postscaler for the Watchdog
Timer (Figure 6-6). For simplicity, this counter is being
referred to as “prescaler” throughout this data sheet.
Note that there is only one prescaler available which is
mutually exclusive between the Timer0 Module and the
Watchdog Timer. Thus, a prescaler assignment for the
Timer0 Module means that there is no prescaler for the
Watchdog Timer, and vice-versa.
The PSA and PS2:PS0 bits (OPTION_REG<3:0>)
determine the prescaler assignment and prescale ratio.
When assigned to the Timer0 Module, all instructions
writing to the Timer0 Module (e.g.,
CLRF 1, MOVWF 1,
BSF 1,x
....etc.) will clear the prescaler. When
assigned to WDT, a
CLRWDT
instruction will clear the
prescaler along with the Watchdog Timer. The
prescaler is not readable or writable.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 16F871 | CAT 5E CROSSOVER PATCH CORD CABLE GREEN 6 FT |
| 16F872 | CAT 5E CROSSOVER PATCH CORD CABLE GREEN 10 FT |
| 16F876A | 28/40-pin Enhanced FLASH Microcontrollers |
| 16F876 | CAT 5E CROSSOVER, GREEN 15 FT PATCH CABLE |
| 16F877 | CAT 5E CROSSOVER PATCH CORD CABLE GREEN 20 FT |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 16F870 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-Pin 8-Bit CMOS FLASH Microcontrollers |
| 16F871 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-Pin 8-Bit CMOS FLASH Microcontrollers |
| 16F872 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28-Pin, 8-Bit CMOS FLASH Microcontroller |
| 16F876 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-pin 8-Bit CMOS FLASH Microcontrollers |
| 16F876A | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-pin Enhanced FLASH Microcontrollers |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。