AT89LP51ED2-20AAU Atmel, AT89LP51ED2-20AAU Datasheet - Page 208

• Manufacturer Part Number: AT89LP51ED2-20AAU
• Description: 8-bit Microcontrollers - MCU 64KB 20MHz 2.4V-5.5V
• Manufacturer: Atmel

Specifications of AT89LP51ED2-20AAU

• Rohs: yes
• Core: 8051
• Processor Series: AT89x
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 20 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 256 B
• On-chip Adc: Yes
• Operating Supply Voltage: 2.4 V to 5.5 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: LQFP-44
• Mounting Style: SMD/SMT
• Data Rom Size: 4 KB
• Interface Type: 2-Wire, SPI, UART
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Program Memory Type: Flash
• Factory Pack Quantity: 160

24.5.4.2
24.5.4.3
24.5.5
24.5.5.1
24.5.5.2
208
AT89LP51RD2/ED2/ID2 Preliminary
Flow Description
Full Chip Erase
Checksum Error
Overview
Communication Initialization
Table 24-17. Software Security Byte Behavior
The ISP command "Full Chip Erase" erases all user Flash memory (fills with FFh) and sets
some bytes used by the bootloader at their default values:
The Full Chip Erase does not affect the bootloader or the EEPROM.
When a checksum error is detected, ‘X’ is sent followed with CR&LF.
An initialization step must be performed after each Reset. After microcontroller reset, the boot-
loader waits for an autobaud sequence (see section
communication is initialized, the protocol depends on the record type requested by the host.
FLIP, a software utility to implement bootloader programming with a PC, is available from the
Atmel web site.
The host initializes the communication by sending a ’U’ character to help the bootloader to com-
pute the baud rate (autobaud).
Figure 24-11. Initialization
Manufacturer Info
• BSB = FFh
• SBV = FCh
• SSB = FFh
Flash/EEPROM
Bootloader Info
Full Chip Erase
Blank Check
BSB & SBV
Erase Block
Fuse Bit
SSB
Communication Opened
Init Communication
Else
If (Not Received "U")
Host
Read-only access allowed
Read-only access allowed
Any access allowed
Any access allowed
Any access allowed
Any access allowed
Allowed
Allowed
Level 0
Allowed
Read-only access allowed
Read-only access allowed
Read-only access allowed
Read-only access allowed
Read-only access allowed
Write level 2 allowed
Not allowed
"U"
Allowed
Allowed
Level 1
"U"
“Autobaud Performance”
Performs Autobaud
Sends Back “U” Characte
Read-only access allowed
Read-only access allowed
Read-only access allowed
Any access not allowed
Any access not allowed
Any access not allowed
Bootloader
Not allowed
Allowed
Allowed
Level 2
3714A–MICRO–7/11
). After the