參數(shù)資料
型號(hào)： PIC17C43
英文描述： PIC17C42/42A/43/44/CR42A/CR43 Datasheet
中文描述： PIC17C42/42A/43/44/CR42A/CR43數(shù)據(jù)表
文件頁(yè)數(shù)： 66/71頁(yè)
文件大小： 1173K
代理商： PIC17C43
1996 Microchip Technology Inc.
DS30412C-page 69
PIC17C4X
11.3
Read/Write Consideration for TMR0
Although TMR0 is a 16-bit timer/counter, only 8-bits at
a time can be read or written during a single instruction
cycle. Care must be taken during any read or write.
11.3.1
READING 16-BIT VALUE
The problem in reading the entire 16-bit value is that
after reading the low (or high) byte, its value may
change from FFh to 00h.
Example 11-1 shows a 16-bit read. To ensure a proper
read, interrupts must be disabled during this routine.
EXAMPLE 11-1: 16-BIT READ
MOVPF
TMR0L, TMPLO
;read low tmr0
MOVPF
TMR0H, TMPHI
;read high tmr0
MOVFP
TMPLO, WREG
;tmplo
> wreg
CPFSLT
TMR0L
;tmr0l < wreg?
RETURN
;no then return
MOVPF
TMR0L, TMPLO
;read low tmr0
MOVPF
TMR0H, TMPHI
;read high tmr0
RETURN
;return
11.3.2
WRITING A 16-BIT VALUE TO TMR0
Since writing to either TMR0L or TMR0H will effectively
inhibit increment of that half of the TMR0 in the next
cycle (following write), but not inhibit increment of the
other half, the user must write to TMR0L rst and
TMR0H next in two consecutive instructions, as shown
in Example 11-2. The interrupt must be disabled. Any
write to either TMR0L or TMR0H clears the prescaler.
EXAMPLE 11-2: 16-BIT WRITE
BSF
CPUSTA, GLINTD ; Disable interrupt
MOVFP RAM_L, TMR0L
;
MOVFP RAM_H, TMR0H
;
BCF
CPUSTA, GLINTD ; Done, enable interrupt
11.4
Prescaler Assignments
Timer0 has an 8-bit prescaler. The prescaler assign-
ment is fully under software control; i.e., it can be
changed “on the y” during program execution. When
changing the prescaler assignment, clearing the pres-
caler is recommended before changing assignment.
The value of the prescaler is “unknown,” and assigning
a value that is less then the present value makes it dif-
cult to take this unknown time into account.
FIGURE 11-4: TMR0 TIMING: WRITE HIGH OR LOW BYTE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
AD15:AD0
ALE
TMR0L
TMR0H
MOVFP W,TMR0L
Write to TMR0L
MOVFP TMR0L,W
Read TMR0L
(Value = NT0)
MOVFP TMR0L,W
Read TMR0L
(Value = NT0)
MOVFP TMR0L,W
Read TMR0L
(Value = NT0 +1)
T0
T0+1
New T0 (NT0)
New T0+1
PC
PC+1
PC+2
PC+3
PC+4
Fetch
Instruction
executed
相關(guān)PDF資料
PDF描述
PIC17C75X Micropower Precision Series Reference Family; Package: SOT; No of Pins: 3; Temperature Range: 0&deg;C to +70&deg;C
PIC17C7X
PIC17C44 Low Power 5V RS232 Dual Driver/Receiver with 0.1?μF Capacitors; Package: SO; No of Pins: 16; Temperature Range: -40?°C to 85?°C
PIC17C766T-33E/L 8-BIT, OTPROM, 33 MHz, RISC MICROCONTROLLER, PQCC84
PIC18C242-I/SO 8-BIT, OTPROM, 40 MHz, RISC MICROCONTROLLER, PDSO28
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC17C43/JW 功能描述:8位微控制器 -MCU 64KB 3328 RAM w/ECAN RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) 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(fēng)格:SMD/SMT
PIC17C43-16/L 功能描述:8位微控制器 -MCU 8KB 454 RAM 33 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) 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(fēng)格:SMD/SMT
PIC17C43-16/L 制造商:Microchip Technology Inc 功能描述:8BIT CMOS MCU SMD 17C43 PLCC44
PIC17C43-16/P 功能描述:8位微控制器 -MCU 8KB 454 RAM 33 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) 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(fēng)格:SMD/SMT
PIC17C43-16/P 制造商:Microchip Technology Inc 功能描述:IC 8BIT CMOS MCU OTP 17C43 DIP40
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*