参数资料
| 型号： | AT89S52-24JI |
| 厂商： | Atmel |
| 文件页数： | 7/37页 |
| 文件大小： | 0K |
| 描述： | IC MCU 8K FLASH 24MHZ 44-PLCC |
| 标准包装： | 27 |
| 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-LCC（J 形引线） |
| 包装： | 管件 |
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15
1919D–MICRO–6/08
AT89S52
11. Baud Rate Generator
Timer 2 is selected as the baud rate generator by setting TCLK and/or RCLK in T2CON (Table
5-2). Note that the baud rates for transmit and receive can be different if Timer 2 is used for the
receiver or transmitter and Timer 1 is used for the other function. Setting RCLK and/or TCLK
puts Timer 2 into its baud rate generator mode, as shown in Figure 11-1.
The baud rate generator mode is similar to the auto-reload mode, in that a rollover in TH2
causes the Timer 2 registers to be reloaded with the 16-bit value in registers RCAP2H and
RCAP2L, which are preset by software.
The baud rates in Modes 1 and 3 are determined by Timer 2’s overflow rate according to the fol-
lowing equation.
The Timer can be configured for either timer or counter operation. In most applications, it is con-
figured for timer operation (CP/T2 = 0). The timer operation is different for Timer 2 when it is
used as a baud rate generator. Normally, as a timer, it increments every machine cycle (at 1/12
the oscillator frequency). As a baud rate generator, however, it increments every state time (at
1/2 the oscillator frequency). The baud rate formula is given below.
where (RCAP2H, RCAP2L) is the content of RCAP2H and RCAP2L taken as a 16-bit unsigned
integer.
Timer 2 as a baud rate generator is shown in Figure 11-1. This figure is valid only if RCLK or
TCLK = 1 in T2CON. Note that a rollover in TH2 does not set TF2 and will not generate an inter-
rupt. Note too, that if EXEN2 is set, a 1-to-0 transition in T2EX will set EXF2 but will not cause a
reload from (RCAP2H, RCAP2L) to (TH2, TL2). Thus, when Timer 2 is in use as a baud rate
generator, T2EX can be used as an extra external interrupt.
Note that when Timer 2 is running (TR2 = 1) as a timer in the baud rate generator mode, TH2 or
TL2 should not be read from or written to. Under these conditions, the Timer is incremented
every state time, and the results of a read or write may not be accurate. The RCAP2 registers
may be read but should not be written to, because a write might overlap a reload and cause
write and/or reload errors. The timer should be turned off (clear TR2) before accessing the Timer
2 or RCAP2 registers.
Modes 1 and 3 Baud Rates
Timer 2 Overflow Rate
16
------------------------------------------------------------
=
Modes 1 and 3
Baud Rate
---------------------------------------
Oscillator Frequency
32 x [65536-RCAP2H,RCAP2L)]
--------------------------------------------------------------------------------------
=
相关PDF资料 |
PDF描述 |
|---|---|
| AT89S52-24JC | IC MCU 8K FLASH 24MHZ 44-PLCC |
| AT89S52-24AI | IC MCU 8K FLASH 24MHZ 44-TQFP |
| 10FMN-SMT-A-TF | CONN FMN HOUSING 10POS SIDE SMD |
| 09FMN-SMT-A-TF | CONN FMN HOUSING 9POS SIDE SMD |
| 08FMN-SMT-A-TF | CONN FMN HOUSING 8POS SIDE SMD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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 |
| AT89S52-24JJ | 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 |
| AT89S52-24JU | 功能描述:8位微控制器 -MCU 8kB Flash 256B RAM 33MHz 4.0V-5.5V 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 |
| AT89S52-24JU SL383 | 制造商:Atmel Corporation 功能描述:MCU 8-bit AT89 80C51 CISC 8KB Flash 5V 44-Pin PLCC T/R |
| AT89S52-24PC | 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 |
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