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参数资料
型号： AT89S4051-24PU
厂商： ATMEL CORP
元件分类： 微控制器/微处理器
英文描述： 8-bit Microcontroller with 2K/4K Bytes Flash
中文描述： 8-BIT, FLASH, 24 MHz, MICROCONTROLLER, PDIP20
封装： 0.300 INCH, GREEN, MS-001AD, PLASTIC, DIP-20
文件页数： 14/45页
文件大小： 981K
代理商： AT89S4051-24PU
14
3390C–MICRO–7/05
AT89S2051/S4051
15. Timer/Counters
The AT89S2051/S4051 have two 16-bit Timer/Counters: Timer 0 and Timer 1. The
Timer/Counters are identical to those in the AT89C2051/C4051. For more detailed information
on the Timer/Counter operation, please click on the document link below:
16. Pulse Width Modulation
Timer 0 and Timer 1 may be configured as an 8-bit pulse width modulator by setting the PWMEN
bit in PCON. The generated waveform is output on the Timer 1 input pin, T1. In PWM mode
Timer 0 acts as an 8-bit prescaler to select the PWM timebase. Timer 0 is forced into Mode 2 (8-
bit auto-reload) by PWMEN and the value in TH0 will determine the clock division from 0 (FFh)
to 256 (00h). Timer 1 acts as the 8-bit PWM counter. TL1 counts once on every overflow from
TL0. TH1 stores the 8-bit pulse width value. On the FFh-->00h overflow of TL1, the PWM output
is set high. When the count in TL1 matches the value in TH1, the PWM output is set low. There-
fore, the output pulse width is proportional to the value in TH1. To prevent glitches, writes to TH1
only take effect on the FFh-->00h overflow of TL1. However, a read from TH1 will read the new
value at any time after a write to TH1. See
Figure 16-1
for PWM waveform example.
Figure 16-1.
Pulse Width Modulation (PWM) Output Waveform
Figure 16-2.
Timer 0/1 Pulse Width Modulation Mode
TL0 counts once every machine cycle (1 machine cycle = 12 clocks in X1 mode) and TH0 is the
reload value for when TL0 overflows. Every time TL0 overflows TL1 increments by one, with TL0
overflowing after counting 256 minus TH0 machine cycles.
To calculate the pulse width for the PWM output on pin T1, users should use the following
formula:
TH1 * (256 - TH0) * (1/clock_freq) * 12 = Pulse Width
PWM Output (T1)
Counter Value (TL1)
Compare Value (TH1)
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C
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T
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0
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相关PDF资料
PDF描述
AT89S4051-24SC 8-bit Microcontroller with 2K/4K Bytes Flash
AT89S4051-24SI 8-bit Microcontroller with 2K/4K Bytes Flash
AT89S4051-24SU 8-bit Microcontroller with 2K/4K Bytes Flash
AT89S4D12 8-Bit Microcontroller with 132K Bytes Flash Data Memory
AT89S4D12-12JC 8-Bit Microcontroller with 132K Bytes Flash Data Memory
相关代理商/技术参数
参数描述
AT89S4051-24SU 功能描述:8位微控制器 -MCU 4K FLASH 24MHZ RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT89S4051-24SUR 功能描述:8051 89S Microcontroller IC 8-Bit 24MHz 4KB (4K x 8) FLASH 20-SOIC 制造商:atmel 系列:89S 包装:管件 零件状态:有效 核心处理器:8051 核心尺寸:8-位 速度:24MHz 连接性:UART/USART 外设:欠压检测/复位，POR，PWM I/O 数:15 程序存储容量:4KB（4K x 8） 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:256 x 8 电压 - 电源（Vcc/Vdd）:2.7 V ~ 5.5 V 数据转换器:- 振荡器类型:内部 工作温度:-40°C ~ 85°C（TA） 封装/外壳:20-SOIC（0.295"，7.50mm 宽） 供应商器件封装:20-SOIC 标准包装:37
AT89S4D12-12RC 功能描述:8位微控制器 -MCU Microcontroller RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT89S4D12-12RI 功能描述:8位微控制器 -MCU Microcontroller RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT89S51-24AC 功能描述:8位微控制器 -MCU 4K ISP FLASH 2.7 TO 5.5V - 24 MHZ RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
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