參數資料
型號: PIC12HV615
廠商: Microchip Technology Inc.
英文描述: 8-Pin Flash-Based, 8-Bit CMOS Microcontrollers
中文描述: 8引腳閃存的基礎上,8位CMOS微控制器
文件頁數: 49/168頁
文件大?。?/td> 1347K
代理商: PIC12HV615
2006 Microchip Technology Inc.
Preliminary
DS41302A-page 47
PIC12F609/615/12HV609/615
6.2.1
INTERNAL CLOCK SOURCE
When the internal clock source is selected, the
TMR1H:TMR1L register pair will increment on multiples
of T
CY
as determined by the Timer1 prescaler.
6.2.2
EXTERNAL CLOCK SOURCE
When the external clock source is selected, the Timer1
module may work as a timer or a counter.
When counting, Timer1 is incremented on the rising
edge of the external clock input T1CKI. In addition, the
Counter mode clock can be synchronized to the
microcontroller system clock or run asynchronously.
If an external clock oscillator is needed (and the
microcontroller is using the INTOSC without CLKOUT),
Timer1 can use the LP oscillator as a clock source.
In Counter mode, a falling edge must be registered by
the counter prior to the first incrementing rising edge
after one or more of the following conditions:
Timer1 is enabled after POR or BOR Reset
A write to TMR1H or TMR1L
T1CKI is high when Timer1 is disabled and when
Timer1 is reenabled T1CKI is low. See Figure 6-2.
6.3
Timer1 Prescaler
Timer1 has four prescaler options allowing 1, 2, 4 or 8
divisions of the clock input. The T1CKPS bits of the
T1CON register control the prescale counter. The
prescale counter is not directly readable or writable;
however, the prescaler counter is cleared upon a write to
TMR1H or TMR1L.
6.4
Timer1 Oscillator
A low-power 32.768 kHz crystal oscillator is built-in
between pins OSC1 (input) and OSC2 (output). The
oscillator is enabled by setting the T1OSCEN control
bit of the T1CON register. The oscillator will continue to
run during Sleep.
The Timer1 oscillator is shared with the system LP
oscillator. Thus, Timer1 can use this mode only when
the primary system clock is derived from the internal
oscillator or when in LP oscillator mode. The user must
provide a software time delay to ensure proper oscilla-
tor start-up.
TRISIO5 and TRISIO4 bits are set when the Timer1
oscillator is enabled. GP5 and GP4 bits read as ‘
0
’ and
TRISIO5 and TRISIO4 bits read as ‘
1
’.
6.5
Timer1 Operation in
Asynchronous Counter Mode
If control bit T1SYNC of the T1CON register is set, the
external clock input is not synchronized. The timer
continues to increment asynchronous to the internal
phase clocks. The timer will continue to run during
Sleep and can generate an interrupt on overflow,
which will wake-up the processor. However, special
precautions in software are needed to read/write the
timer (see
Section 6.5.1 “Reading and Writing
Timer1 in Asynchronous Counter Mode”
).
6.5.1
READING AND WRITING TIMER1 IN
ASYNCHRONOUS COUNTER
MODE
Reading TMR1H or TMR1L while the timer is running
from an external asynchronous clock will ensure a valid
read (taken care of in hardware). However, the user
should keep in mind that reading the 16-bit timer in two
8-bit values itself poses certain problems, since the
timer may overflow between the reads.
For writes, it is recommended that the user simply stop
the timer and write the desired values. A write
contention may occur by writing to the timer registers,
while the register is incrementing. This may produce an
unpredictable value in the TMR1H:TTMR1L register
pair.
6.6
Timer1 Gate
Timer1 gate source is software configurable to be the
T1G pin (or the alternate T1G pin) or the output of the
Comparator. This allows the device to directly time
external events using T1G or analog events using the
Comparator. See the CMCON1 Register (Register 8-2)
for selecting the Timer1 gate source. This feature can
simplify the software for a Delta-Sigma A/D converter
and many other applications. For more information on
Delta-Sigma A/D converters, see the Microchip web site
(www.microchip.com).
Timer1 gate can be inverted using the T1GINV bit of
the T1CON register, whether it originates from the T1G
pin or the Comparator output. This configures Timer1 to
measure either the active-high or active-low time
between events.
Note:
The oscillator requires a start-up and
stabilization time before use. Thus,
T1OSCEN should be set and a suitable
delay observed prior to enabling Timer1.
Note:
When switching from synchronous to
asynchronous operation, it is possible to
skip an increment. When switching from
asynchronous to synchronous operation,
it is possible to produce a single spurious
increment.
Note:
TMR1GE bit of the T1CON register must
be set to use either T1G or COUT as the
Timer1 gate source. See Register 8-2 for
more information on selecting the Timer1
gate source.
相關PDF資料
PDF描述
PIC16C505-04 14-Pin, 8-Bit CMOS Microcontroller
PIC16C505 14-Pin, 8-Bit CMOS Microcontroller(每個I/O口有25mA驅動/吸收電流,12個I/O口,帶WDT的微控制器)
PIC16C54C EPROM/ROM-Based 8-Bit CMOS Microcontroller(18引腳、12個I/O端口、512位EPROM/ROM的8位CMOS微控制器)
PIC16C54 EPROM/ROM-Based 8-Bit CMOS Microcontroller Series(每個I/O口有20mA吸收,25mA驅動,12個I/O,2.5V的微控制器)
PIC16CR54B EPROM/ROM-Based 8-Bit CMOS Microcontroller Series(每個I/O口有20mA吸收,25mA驅動,12個I/O,2.5V的微控制器)
相關代理商/技術參數
參數描述
PIC12HV615-E/MD 功能描述:8位微控制器 -MCU 2KB Flash 64 RAM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數據總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數據 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 安裝風格:SMD/SMT
PIC12HV615-E/MF 功能描述:8位微控制器 -MCU 1.75KB Flash 64B RAM 6 I/O 8MHz INT OSC RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數據總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數據 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 安裝風格:SMD/SMT
PIC12HV615-E/MS 功能描述:8位微控制器 -MCU 2KB Flash 64 RAM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數據總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數據 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 安裝風格:SMD/SMT
PIC12HV615-E/P 功能描述:8位微控制器 -MCU 2KB Flash 64 RAM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數據總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數據 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 安裝風格:SMD/SMT
PIC12HV615-E/SN 功能描述:8位微控制器 -MCU 2KB Flash 64 RAM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數據總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數據 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 安裝風格:SMD/SMT