AT89C51RB2 Atmel Corporation, AT89C51RB2 Datasheet - Page 97

• Manufacturer Part Number: AT89C51RB2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RB2

• Flash (kbytes): 16 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 1.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

Full Chip Erase
Checksum Error
Flow Description
Overview
Communication Initialization
4180E–8051–10/06
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.
When a checksum error is detected send ‘X’ followed with CR&LF.
An initialization step must be performed after each Reset. After microcontroller reset,
the bootloader waits for an autobaud sequence ( see section ‘autobaud performance’).
When the communication is initialized the protocol depends on the record type
requested by the host.
FLIP, a software utility to implement ISP programming with a PC, is available from the
Atmel the web site.
The host initializes the communication by sending a ’U’ character to help the bootloader
to compute the baudrate (autobaud).
Figure 40. Initialization
BSB = FFh
SBV = FCh
SSB = FFh and finally erase the Software Security Bits
Communication Opened
Init Communication
Else
If (not received "U")
Host
"U"
"U"
AT89C51RB2/RC2
Sends Back ‘U’ Character
Performs Autobaud
Bootloader
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