AT89C51ED2-RLRUM Atmel, AT89C51ED2-RLRUM Datasheet - Page 100
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AT89C51ED2-RLRUM
Manufacturer Part Number
AT89C51ED2-RLRUM
Description
IC MCU FLASH 8051 64K 5V 44-VQFP
Manufacturer
Atmel
Series
89Cr
Datasheet
1.ATWEBDVK-02RC.pdf
(137 pages)
Specifications of AT89C51ED2-RLRUM
Core Processor
8051
Core Size
8-Bit
Speed
60MHz
Connectivity
SPI, UART/USART
Peripherals
POR, PWM, WDT
Number Of I /o
34
Program Memory Size
64KB (64K x 8)
Program Memory Type
FLASH
Eeprom Size
2K x 8
Ram Size
2K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Oscillator Type
External
Operating Temperature
-40°C ~ 85°C
Package / Case
44-TQFP, 44-VQFP
Core
8051
Processor Series
AT89x
Data Bus Width
8 bit
Maximum Clock Frequency
60 MHz
Data Ram Size
2 KB
Number Of Programmable I/os
32
Number Of Timers
3
Operating Supply Voltage
2.7 V to 5.5 V
Mounting Style
SMD/SMT
Interface Type
UART, SPI
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Data Converters
-
Lead Free Status / Rohs Status
Details
Available stocks
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Part Number
Manufacturer
Quantity
Price
24.6.4
Figure 24-4. Hardware conditions typical sequence during power-on.
100
AT89C51RD2/ED2
Bootloader Functionality
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 a an output port in normal operating mode after reset, user application should take
care 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
The on-chip bootloader boot process is shown
Table 24-6.
Hardware Conditions
BLJB
SBV
VCC
PSEN
RST
Bootloader Process Description
Figure
24-4).
Purpose
The Hardware Conditions force the bootloader execution whatever BLJB,
BSB and SBV values.
The Boot Loader Jump Bit forces the application execution.
BLJB = 0 => Bootloader execution
BLJB = 1 => Application execution
The BLJB is a fuse bit in the Hardware Byte.
It can be modified by hardware (programmer) or by software (API).
Note: The BLJB test is performed by hardware to prevent any program
execution.
The Software Boot Vector contains the high address of customer bootloader
stored in the application.
SBV = FCh (default value) if no customer bootloader in user Flash.
Note: The customer bootloader is called by JMP [SBV]00h instruction.
Figure
24-5.
4235K–8051–05/08