AT89C51RC2_0312 Datasheet, PDF (97/127 Pages) ATMEL Corporation – Microcontroller with 16K/32K Bytes Flash

AT89C51RB2/RC2
Full Chip Erase
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:
• BSB = FFh
• SBV = FCh
• SSB = FFh and finally erase the Software Security Bits
The Full Chip Erase does not affect the bootloader.
Checksum Error
When a checksum error is detected send ‘X’ followed with CR&LF.
Flow Description
Overview
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.
Communication Initialization The host initializes the communication by sending a ’U’ character to help the bootloader
to compute the baudrate (autobaud).
Figure 40. Initialization
Host
Bootloader
Init Communication
"U"
Performs Autobaud
If (not received "U")
Else
Communication Opened
Sends Back ‘U’ Character
"U"
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