at89c51snd1 ATMEL Corporation, at89c51snd1 Datasheet - Page 17

• Manufacturer Part Number: at89c51snd1
• Description: Mp3 Microcontrollers
• Manufacturer: ATMEL Corporation

Read Example
Erase the Flash
Requests from Host
Answers from Bootloader
4241B–MP3–07/04
The flow described in Figure 11 allows the user to erase the Flash memory.
Two modes of Flash erasing are possible:
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The Full Chip erase command erases the whole Flash and sets some Configuration
Bytes at their default values:
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The full chip erase is always executed whatever the Software Security Byte value is.
The Block erase command erases only a part of the Flash.
Four Blocks are defined in the AT89C51SND1:
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As the Program Configuration Information flows, the erase block command has three
possible answers:
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Command Name
Erase block0 (0k to 8k)
Erase block1 (8k to 16k)
Erase block2 (16k to 32k)
Erase block2 (32k to 64k)
Full chip erase
Read function (read SBV)
Atmel Read function (read bootloader version)
HOST
BOOTLOADER
HOST
BOOTLOADER
Full Chip erase
Block erase
BSB = FFh
SBV = F0h
SSB = FFh (NO_SECURITY)
block0 (From 0000h to 1FFFh)
block1 (From 2000h to 3FFFh)
block2 (From 4000h to 7FFFh)
block3 (From 8000h to FFFFh)
“.” & “CR” & “LF” when the data are programmed
“X” & “CR” & “LF” if the checksum is wrong
“P” & “CR” & ”LF” if the Security is set
: 02 0000 05 07 02 F0
: 02 0000 05 07 02 F0 Value . CR LF
: 02 0000 01 02 00 FB
: 02 0000 01 02 00 FB Value . CR LF
AT89C51SND1 UART Bootloader
Record
Type
03h
Offset
Load
x
Record
Length
02h
01h
Data[0]
01h
07h
Data[1]
00h
20h
40h
80h
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