參數(shù)資料
型號: PIC16C642
廠商: Microchip Technology Inc.
英文描述: 8-Bit EPROM Microcontrollers with Analog Comparators(每個I/O口有25mA驅動/吸收電流,可編程Vref,微控制器)
中文描述: 8位EPROM微控制器與模擬比較器(每個的I / O口有25毫安驅動/吸收電流,可編程Vref的,微控制器)
文件頁數(shù): 41/136頁
文件大小: 837K
代理商: PIC16C642
1996 Microchip Technology Inc.
Preliminary
DS30559A-page 41
PIC16C64X & PIC16C66X
6.0
TIMER0 MODULE
The Timer0 module has the following features:
8-bit timer/counter register, TMR0
- Read and write capability
- Interrupt on overflow from FFh to 00h
8-bit software programmable prescaler
Internal or external clock select
- Edge select for external clock
Figure 6-1 is a simplified block diagram of the Timer0
module.
Timer mode is selected by clearing bit T0CS
(OPTION<5>). In timer mode, the Timer0 module will
increment every instruction cycle (without prescaler). If
TMR0 register is written, the increment is inhibited for
the following two instruction cycles (Figure 6-2 and
Figure 6-3). The user can work around this by writing
an adjusted value to the TMR0 register.
Counter mode is selected by setting bit T0CS. In this
mode, Timer0 will increment either on every rising or
falling edge of pin RA4/T0CKI. The incrementing edge
is determined by the source edge select bit T0SE
(OPTION<4>). Clearing bit T0SE selects the rising
edge. Restrictions on the external clock input are dis-
cussed in detail in Section 6.2.
The prescaler is mutually exclusively shared between
the Timer0 module and the Watchdog Timer. The pres-
caler assignment is controlled in software by control bit
PSA (OPTION<3>). Clearing bit PSA will assign the
prescaler to the Timer0 module. The prescaler is not
readable or writable. When the prescaler is assigned to
the Timer0 module, prescale values of 1:2, 1:4, …,
1:256 are selectable. Section 6.3 details the operation
of the prescaler.
6.1
The TMR0 interrupt is generated when the register
(TMR0) overflows from FFh to 00h. This overflow sets
interrupt flag bit T0IF (INTCON<2>). The interrupt can
be masked by clearing enable bit T0IE (INTCON<5>).
Flag bit T0IF must be cleared in software by the Timer0
interrupt service routine before re-enabling this inter-
rupt. The TMR0 interrupt cannot wake the processor
from SLEEP since the timer is shut off during SLEEP.
Figure 6-4 displays the Timer0 interrupt timing.
Timer0 Interrupt
FIGURE 6-1:
TIMER0 BLOCK DIAGRAM
FIGURE 6-2:
TIMER0 TIMING: INTERNAL CLOCK/NO PRESCALER
Note 1:
Bits, T0CS, T0SE, PSA, and PS2, PS1, PS0 are (OPTION<5:0).
The prescaler is shared with Watchdog Timer (refer to Figure 6-6 for detailed diagram).
2:
RA4/T0CKI
pin
T0SE
0
1
1
0
T0CS
F
OSC
/4
Programmable
Prescaler
Sync with
Internal
clocks
TMR0 reg
PSout
(2 cycle delay)
PSout
Data bus
8
Set bit T0IF
on overflow
PSA
PS2, PS1, PS0
3
PC-1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
PC
(Program
Counter)
Instruction
Fetch
TMR0
PC
PC+1
PC+2
PC+3
PC+4
PC+5
PC+6
T0
T0+1
T0+2
NT0
NT0
NT0
NT0+1
NT0+2
MOVWF TMR0
MOVF TMR0,W
MOVF TMR0,W
MOVF TMR0,W
MOVF TMR0,W
MOVF TMR0,W
Write TMR0
executed
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0
Read TMR0
reads NT0 + 1
Read TMR0
reads NT0 + 2
Instruction
Executed
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相關代理商/技術參數(shù)
參數(shù)描述
PIC16C642/JW 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)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(shù)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
PIC16C642-04/SO 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)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(shù)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
PIC16C642-04/SP 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)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(shù)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
PIC16C642-04E/SO 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)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(shù)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
PIC16C642-04E/SP 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)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(shù)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