Datasheet

118
AT89C51IC2
4301D–8051–02/08
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 47. Initialization
Host
Bootloader
"U"
Performs Autobaud
Init Communication
If (not received "U")
"U"
Communication Opened
Else
Sends Back ‘U’ Character