參數(shù)資料
型號(hào)： AT90LS2343-1PI
廠商： Atmel
文件頁(yè)數(shù)： 35/63頁(yè)
文件大?。?/td> 0K
描述： IC MCU 2K FLASH 1MHZ IND 8-DIP
標(biāo)準(zhǔn)包裝： 50
系列： AVR® 90LS
核心處理器： AVR
芯體尺寸： 8-位
速度： 1MHz
連通性： SPI
外圍設(shè)備： 欠壓檢測(cè)/復(fù)位，POR，WDT
輸入/輸出數(shù)： 5
程序存儲(chǔ)器容量： 2KB（1K x 16）
程序存儲(chǔ)器類(lèi)型： 閃存
EEPROM 大?。?/td> 128 x 8
RAM 容量： 128 x 8
電壓 - 電源 (Vcc/Vdd)： 2.7 V ~ 6 V
振蕩器型： 內(nèi)部
工作溫度： -40°C ~ 85°C
封裝/外殼： 8-DIP（0.300"，7.62mm）
包裝： 管件
2002 Microchip Technology Inc.
Preliminary
DS41139B-page 39
PIC16C433
7.2
Using Timer0 with an External Clock
When an external clock input is used for Timer0, it must
meet certain requirements. The requirements ensure
the external clock can be synchronized with the internal
phase clock (TOSC). Also, there is a delay in the actual
incrementing of Timer0 after synchronization.
7.2.1
EXTERNAL CLOCK SYNCHRONIZATION
When no prescaler is used, the external clock input is
used as the clock source. The synchronization of
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 7-5). There-
fore, it is necessary for T0CKI to be high for at least
2TOSC (and a small RC delay of 20 ns) and low for at
least 2TOSC (and a small RC delay of 20 ns). Refer to
the electrical specification of the desired device.
When a prescaler is used, the external clock input is
divided by the asynchronous ripple-counter type pres-
caler, so that the prescaler output is symmetrical. For
the external clock to meet the sampling requirement,
the ripple-counter must be taken into account. There-
fore, it is necessary for T0CKI to have a period of at
least 4TOSC (and a small RC delay of 40 ns), divided by
the prescaler value. The only requirement on T0CKI
high and low time is that they do not violate the mini-
mum pulse width requirement of 10 ns. Refer to param-
eters 40, 41 and 42 in the electrical specification of the
desired device.
7.2.2
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 mod-
ule is actually incremented. Figure 7-5 shows the delay
from the external clock edge to the timer incrementing.
FIGURE 7-5:
TIMER0 TIMING WITH EXTERNAL CLOCK
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
External Clock Input or
Prescaler Output(2)
External Clock/Prescaler
Output after Sampling
Increment Timer0 (Q4)
Timer0
T0
T0 + 1
T0 + 2
Small pulse
misses sampling
(3)
(1)
Note 1:
Delay from clock input change to Timer0 increment is 3T
OSC to 7TOSC (Duration of Q = TOSC). Therefore, the error in measuring
the interval between two edges on Timer0 input = ±4T
OSC max.
2:
External clock if no prescaler selected; prescaler output otherwise.
3:
The arrows indicate the points in time where sampling occurs.
相關(guān)PDF資料
PDF描述
AT90LS2343-1PC IC MCU 2K FLASH 1MHZ COM 8-DIP
AT89S52-24PI IC MCU 8K FLASH 24MHZ 40-DIP
DSPIC33FJ32MC202-I/SS IC DSPIC MCU/DSP 32K 28SSOP
PIC18LF46J13-I/ML IC PIC MCU 64KB FLASH 44QFN
52892-1890 CONN FFC 18POS .50MM R/A ZIF SMD
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AT90LS2343-1SC 功能描述:IC MCU 2K FLASH 1MHZ COM 8-SOIC RoHS:否 類(lèi)別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:AVR® 90LS 標(biāo)準(zhǔn)包裝:9 系列:87C 核心處理器:8051 芯體尺寸:8-位 速度:40/20MHz 連通性:UART/USART 外圍設(shè)備:POR，WDT 輸入/輸出數(shù):32 程序存儲(chǔ)器容量:32KB（32K x 8） 程序存儲(chǔ)器類(lèi)型:OTP EEPROM 大小:- RAM 容量:256 x 8 電壓 - 電源 (Vcc/Vdd):4.5 V ~ 5.5 V 數(shù)據(jù)轉(zhuǎn)換器:- 振蕩器型:內(nèi)部 工作溫度:0°C ~ 70°C 封裝/外殼:40-DIP（0.600"，15.24mm） 包裝:管件
AT90LS2343-1SI 功能描述:8位微控制器 -MCU 2k bit RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)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
AT90LS2343-4PC 功能描述:8位微控制器 -MCU 2k bit RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)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
AT90LS2343-4PI 功能描述:8位微控制器 -MCU 2k bit RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)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
AT90LS2343-4SC 制造商:ATMEL 制造商全稱(chēng):ATMEL Corporation 功能描述:8-Bit Microcontroller with 2K Bytes of In-System Programmable Flash
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

*
*
*