參數(shù)資料
型號: AT89C51RB2-SLSUM
廠商: Atmel
文件頁數(shù): 121/127頁
文件大小: 0K
描述: IC 8051 MCU FLASH 16K 44PLCC
產品培訓模塊: MCU Product Line Introduction
標準包裝: 972
系列: 89C
核心處理器: 8051
芯體尺寸: 8-位
速度: 60MHz
連通性: SPI,UART/USART
外圍設備: POR,PWM,WDT
輸入/輸出數(shù): 32
程序存儲器容量: 16KB(16K x 8)
程序存儲器類型: 閃存
RAM 容量: 1.25K x 8
電壓 - 電源 (Vcc/Vdd): 2.7 V ~ 5.5 V
振蕩器型: 外部
工作溫度: -40°C ~ 85°C
封裝/外殼: 44-LCC(J 形引線)
包裝: 管件
配用: AT89OCD-01-ND - USB EMULATOR FOR AT8XC51 MCU
AT89STK-11-ND - KIT STARTER FOR AT89C51RX2
93
AT89C51RB2/RC2
4180E–8051–10/06
Bootloader Functionality
Introduction
The bootloader can be activated by two means: Hardware conditions or regular boot
process.
The Hardware conditions (EA = 1, PSEN = 0) during the Reset# falling edge force the
on-chip bootloader execution. This allows an application to be built that will normally
execute the end user’s code but can be manually forced into default ISP operation.
As PSEN is an output port in normal operating mode (running user application or boor-
loader code) after reset, it is recommended to release PSEN after falling edge of reset
signal. The hardware conditions are sampled at reset signal falling edge, thus they can
be released at any time when reset input is low.
To ensure correct microcontroller startup, the PSEN pin should not be tied to ground
during power-on (See Figure 38).
Figure 38. Hardware conditions typical sequence during power-on.
The on-chip bootloader boot process is shown in Figure 39.
VCC
PSEN
RST
Purpose
Hardware Conditions
The Hardware Conditions force the bootloader execution whatever BLJB, BSB
and SBV values.
BLJB
The Boot Loader Jump Bit forces the application execution.
BLJB = 0 => Boot loader execution.
BLJB = 1 => Application execution.
The BLJB is a fuse bit in the Hardware Byte.
That can be modified by hardware (programmer) or by software (API).
Note:
The BLJB test is perform by hardware to prevent any program execution.
SBV
The Software Boot Vector contains the high address of custumer bootloader
stored in the application.
SBV = FCh (default value) if no custumer bootloader in user Flash.
Note:
The costumer bootloader is called by JMP [SBV]00h instruction.
相關PDF資料
PDF描述
VJ1825A152JBLAT4X CAP CER 1500PF 630V 5% NP0 1825
VJ1825A152KBEAT4X CAP CER 1500PF 500V 10% NP0 1825
VE-B30-CU-B1 CONVERTER MOD DC/DC 5V 200W
ATMEGA644PA-PU IC MCU 8BIT 64KB FLASH 40DIP
VE-B2W-IY-F4 CONVERTER MOD DC/DC 5.5V 50W
相關代理商/技術參數(shù)
參數(shù)描述
AT89C51RC 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:8-bit Microcontroller with 32K Bytes Flash
AT89C51RC_05 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:8-bit Microcontroller with 32K Bytes Flash
AT89C51RC_08 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:8-bit Microcontroller with 32K Bytes Flash
AT89C51RC2 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:8-bit Microcontroller with 16K/ 32K Bytes Flash
AT89C51RC2_0312 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Microcontroller with 16K/32K Bytes Flash