at89c51snd1c ATMEL Corporation, at89c51snd1c Datasheet - Page 14

• Manufacturer Part Number: at89c51snd1c
• Description: At89c51snd1c At89c51snd1 Uart Bootloader
• Manufacturer: ATMEL Corporation

Blank Check Example
Program Configuration
Information
Requests from Host
Answers from Bootloader
14
AT89C51SND1 UART Bootloader
The flow described in Figure 9 allows the user to program Configuration Information
regarding the bootloader functionality.
The Boot Process Configuration:
Note:
The bootloader answers with:
•
•
•
Command Name
Erase SBV & BSB
Program SSB level1
Program SSB level2
Program BSB
Program SBV
Program bit BLJB
Program bit X2
Display data from address 0000h to 0020h
BOOTLOADER
BOOTLOADER
BOOTLOADER
HOST
BOOTLOADER
BSB
SBV
Fuse bits (BLJB and X2 bits) (see Section “Mapping and Default Value of Hardware
Security Byte”, page 3)
SSB
“.” & ”CR” & “LF” when the value is programmed
“X” & “CR” & “LF” if the checksum is wrong
“P” & “CR” & “LF” if the Security is set
1. The field “Load Offset” is not used
2. To program the BLJB and X2 bit the “bit value” is 00h or 01h.
0000=-----data------ CR LF
0010=-----data------ CR LF
0020=data CR LF
: 05 0000 04 0000 0020 00 D7
: 05 0000 04 0000 0020 00 D7
Record
Type
03h
Offset
Load
x
Record
Length
02h
02h
03h
03h
Data[0]
04h
05h
06h
0Ah
(16 data)
(16 data)
(1 data)
Data[1]
00h
00h
01h
00h
01h
04h
08h
4241B–MP3–07/04
Data[2]
bit value
value