Datasheet

13
4266C–CAN–03/08
AT89C51CC03 UART Bootloader
Example
Program
Configuration
Information
The flow described below allows the user to program Configuration Information regarding the
bootloader functionality.
The Boot Process Configuration:
BSB
SBV
Fuse bits (BLJB and X2 bits) (see Section “Mapping and Default Value of Hardware Security
Byte”)
SSB
EB
Requests from Host
Note: 1. The field “Load Offset” is not used
2. To program the BLJB and X2 bit the “bit value” is 00h or 01h.
Answers from
Bootloader
The bootloader answers with:
• ‘.’ & ‘CR’ & ’LF’ when the value is programmed
• ‘X’ & ‘CR’ & ‘LF’ if the checksum is wrong
• ‘P’ & ‘CR’ & ‘LF’ if the Security is set
HOST : 05 0000 04 0000 0020 00 D7
BOOTLOADER
: 05 0000 04 0000 0020 00 D7
BOOTLOADER 0000=-----data------ CR LF (16 data)
BOOTLOADER
0010=-----data------ CR LF (16 data)
BOOTLOADER 0020=data CR LF ( 1 data)
Display data from address 0000h to 0020h
Command Name
Record
Type
Load
Offset
Record
Length Data[0] Data[1] Data[2]
Erase SBV & BSB
03h x
02h 04h 00h -
Program SSB level1
02h 05h
00h -
Program SSB level2 01h -
Program BSB
03h 06h
00h
valueProgram SBV 01h
Program EB 06h
Program bit BLJB
03h 0Ah
04h
bit value
Program bit X2 08h