at89c5131a ATMEL Corporation, at89c5131a Datasheet - Page 22

• Manufacturer Part Number: at89c5131a
• Description: Usb Microcontrollers
• Manufacturer: ATMEL Corporation

Answers from Bootloader
Erasing the Flash
Request from Host
22
AT89C5131A USB Bootloader
The device has two possible answers to a DFU_GETSTATUS request:
•
•
The flow described below allows the user to erase the Flash memory.
Two modes of Flash erasing are possible:
•
•
The Full Chip erase command erases the whole Flash (32 Kbytes) and sets some Con-
figuration Bytes at their default values:
•
•
•
The Block erase command erases only a part of the Flash.
Three Blocks are defined in the AT89C5131A:
•
•
•
To start the erasing operation, the Host sends a DFU_DNLOAD request with a Write
Command in the data field (2 bytes).
Id_write_command
If the chip is protected from program access, an “err_VENDOR” status is returned to
the Host.
Otherwise, the device status is “OK“. The Host can send a DFU_UPLOAD request
to the device in order the value of the requested field.
Full Chip erase
Block erase
BSB = FFh
SBV = FFh
SSB = FFh (NO_SECURITY)
block0 (From 0000h to 1FFFh)
block1 (From 2000h to 3FFFh)
block2 (From 4000h to 7FFFh)
Command
Identifier
04h
SETUP
IN
OUT
data[0]
00h
data[1]
FFh
00h
20h
40h
data[2]
Byte value (1 byte)
DFU_UPLOAD
ZLP
data[3]
data[4]
Erase block0 (0K to 8K)
Erase block1 (8K to 16K)
Erase block2 (16K to 32K)
Full chip Erase (bits at
FFh)
Description
4287C–USB–11/04