参数资料
| 型号： | AT89S52-24AU |
| 厂商： | Atmel |
| 文件页数： | 4/37页 |
| 文件大小： | 0K |
| 描述： | IC MCU 8K FLASH 24MHZ 44-TQFP |
| 产品培训模块： | MCU Product Line Introduction |
| 标准包装： | 160 |
| 系列： | 89S |
| 核心处理器： | 8051 |
| 芯体尺寸： | 8-位 |
| 速度： | 24MHz |
| 连通性： | UART/USART |
| 外围设备： | WDT |
| 输入/输出数： | 32 |
| 程序存储器容量： | 8KB（8K x 8） |
| 程序存储器类型： | 闪存 |
| RAM 容量： | 256 x 8 |
| 电压 - 电源 (Vcc/Vdd)： | 4 V ~ 5.5 V |
| 振荡器型： | 内部 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 44-TQFP |
| 包装： | 托盘 |
| 产品目录页面： | 616 (CN2011-ZH PDF) |
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12
1919D–MICRO–6/08
AT89S52
10. Timer 2
Timer 2 is a 16-bit Timer/Counter that can operate as either a timer or an event counter. The
type of operation is selected by bit C/T2 in the SFR T2CON (shown in Table 5-2). Timer 2 has
three operating modes: capture, auto-reload (up or down counting), and baud rate generator.
The modes are selected by bits in T2CON, as shown in Table 10-1. Timer 2 consists of two 8-bit
registers, TH2 and TL2. In the Timer function, the TL2 register is incremented every machine
cycle. Since a machine cycle consists of 12 oscillator periods, the count rate is 1/12 of the oscil-
lator frequency.
In the Counter function, the register is incremented in response to a 1-to-0 transition at its corre-
sponding external input pin, T2. In this function, the external input is sampled during S5P2 of
every machine cycle. When the samples show a high in one cycle and a low in the next cycle,
the count is incremented. The new count value appears in the register during S3P1 of the cycle
following the one in which the transition was detected. Since two machine cycles (24 oscillator
periods) are required to recognize a 1-to-0 transition, the maximum count rate is 1/24 of the
oscillator frequency. To ensure that a given level is sampled at least once before it changes, the
level should be held for at least one full machine cycle.
10.1
Capture Mode
In the capture mode, two options are selected by bit EXEN2 in T2CON. If EXEN2 = 0, Timer 2 is
a 16-bit timer or counter which upon overflow sets bit TF2 in T2CON. This bit can then be used
to generate an interrupt. If EXEN2 = 1, Timer 2 performs the same operation, but a 1-to-0 transi-
tion at external input T2EX also causes the current value in TH2 and TL2 to be captured into
RCAP2H and RCAP2L, respectively. In addition, the transition at T2EX causes bit EXF2 in
T2CON to be set. The EXF2 bit, like TF2, can generate an interrupt. The capture mode is illus-
trated in Figure 10-1.
10.2
Auto-reload (Up or Down Counter)
Timer 2 can be programmed to count up or down when configured in its 16-bit auto-reload
mode. This feature is invoked by the DCEN (Down Counter Enable) bit located in the SFR
T2MOD (see Table 10-2). Upon reset, the DCEN bit is set to 0 so that timer 2 will default to
count up. When DCEN is set, Timer 2 can count up or down, depending on the value of the
T2EX pin.
Table 10-1.
Timer 2 Operating Modes
RCLK +TCLK
CP/RL2
TR2
MODE
0
1
16-bit Auto-reload
0
1
16-bit Capture
1
X
1
Baud Rate Generator
X
0
(Off)
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AT89S52-24AU SL383 | 制造商:Atmel Corporation 功能描述:8051 8K ISP FLASH 4.0 TO 5.5V |
| AT89S52-24AUR | 功能描述:8051 89S Microcontroller IC 8-Bit 24MHz 8KB (8K x 8) FLASH 44-TQFP (10x10) 制造商:atmel 系列:89S 包装:托盘 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:WDT I/O 数:32 程序存储容量:8KB（8K 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）:4 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:44-TQFP 供应商器件封装:44-TQFP（10x10） 标准包装:160 |
| AT89S52-24JC | 功能描述:8位微控制器 -MCU 8K ISP FLASH 2.7 TO 5.5V - 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 |
| AT89S52-24JI | 功能描述:8位微控制器 -MCU 8K ISP FLASH 2.7 TO 5.5V - 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 |
| AT89S52-24JISL383 | 制造商:Atmel Corporation 功能描述:MCU 8-bit AT89 80C51 CISC 8KB Flash 5V 44-Pin PLCC T/R |
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