t89c51rd2-slscl ATMEL Corporation, t89c51rd2-slscl Datasheet - Page 66

• Manufacturer Part Number: t89c51rd2-slscl
• Description: 0 To 40 Mhz Flash Programmable 8-bit Microcontroller
• Manufacturer: ATMEL Corporation

Full Chip Erase
Checksum Error
Flow Description
Overview
Communication Initialization
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T89C51RD2
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 25. 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"
Sends Back ‘U’ Character
Performs Autobaud
Bootloader
4243G–8051–05/03