参数资料
| 型号： | AT89S51-24JU |
| 厂商： | Atmel |
| 文件页数： | 6/31页 |
| 文件大小： | 0K |
| 描述： | IC MCU 4K FLASH 24MHZ 44-PLCC |
| 产品培训模块： | MCU Product Line Introduction |
| 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： | 4KB（4K x 8） |
| 程序存储器类型： | 闪存 |
| RAM 容量： | 128 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 |
| 产品目录页面： | 616 (CN2011-ZH PDF) |
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14
2487D–MICRO–6/08
AT89S51
14. Program Memory Lock Bits
The AT89S51 has three lock bits that can be left unprogrammed (U) or can be programmed (P)
to obtain the additional features listed in Table 14-1.
When lock bit 1 is programmed, the logic level at the EA pin is sampled and latched during reset.
If the device is powered up without a reset, the latch initializes to a random value and holds that
value until reset is activated. The latched value of EA must agree with the current logic level at
that pin in order for the device to function properly.
15. Programming the Flash – Parallel Mode
The AT89S51 is shipped with the on-chip Flash memory array ready to be programmed. The
programming interface needs a high-voltage (12-volt) program enable signal and is compatible
with conventional third-party Flash or EPROM programmers.
The AT89S51 code memory array is programmed byte-by-byte.
Programming Algorithm: Before programming the AT89S51, the address, data, and control
signals should be set up according to the Flash Programming Modes table (Table 17-1) and Fig-
ure 17-1 and Figure 17-2. To program the AT89S51, take the following steps:
1.
Input the desired memory location on the address lines.
2.
Input the appropriate data byte on the data lines.
3.
Activate the correct combination of control signals.
4.
Raise EA/V
PP to 12V.
5.
Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-
write cycle is self-timed and typically takes no more than 50 s. Repeat steps 1
through 5, changing the address and data for the entire array or until the end of the
object file is reached.
Data Polling: The AT89S51 features Data Polling to indicate the end of a byte write cycle. Dur-
ing a write cycle, an attempted read of the last byte written will result in the complement of the
written data on P0.7. Once the write cycle has been completed, true data is valid on all outputs,
and the next cycle may begin. Data Polling may begin any time after a write cycle has been
initiated.
Ready/Busy: The progress of byte programming can also be monitored by the RDY/BSY output
signal. P3.0 is pulled low after ALE goes high during programming to indicate BUSY. P3.0 is
pulled high again when programming is done to indicate READY.
Table 14-1.
Lock Bit Protection Modes
Program Lock Bits
LB1
LB2
LB3
Protection Type
1
U
No program lock features
2P
U
MOVC instructions executed from external program memory
are disabled from fetching code bytes from internal memory,
EA is sampled and latched on reset, and further programming
of the Flash memory is disabled
3
P
U
Same as mode 2, but verify is also disabled
4
P
Same as mode 3, but external execution is also disabled
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AT89S51-24JU SL383 | 制造商:Atmel Corporation 功能描述:MCU 8-bit AT89 80C51 CISC 4KB Flash 5V 44-Pin PLCC T/R |
| AT89S51-24PC | 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 |
| AT89S51-24PI | 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 |
| AT89S51-24PU | 功能描述:8位微控制器 -MCU 4kB Flash 128B 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 |
| AT89S51-24PU SL383 | 制造商:Atmel Corporation 功能描述:8051 4K ISP FLASH 4.0 TO 5.5V |
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