11

4386B–8051–03/08

AT89C51AC3 UART Bootloader

Read the Flash or

EEPROM Data

The flow described below allows the user to read data in the Flash memory or in the EEPROM

data memory. A blank check command is possible with this flow.

The device splits into blocks of 16 bytes the data to transfer to the Host if the number of data to

display is greater than 16 data bytes.

Requests from Host

Note:

The field “Load offset” is not used.

Answers from

Bootloader

The bootloader answers to a read Flash or EEPROM Data memory command:

•

‘Address = data ‘ & ‘CR’ & ’LF’

up to 16 data by line.

•

‘X’ & ‘CR’ & ‘LF’ if the checksum is wrong

•

‘L’ & ‘CR’ & ‘LF’ if the Security is set

The bootloader answers to blank check command:

•

‘.’ & ‘CR’ & ’LF’ when the blank check is ok

•

‘First Address wrong’ ‘CR’ & ‘LF’ when the blank check is fail

•

‘X’ & ‘CR’ & ‘LF’ if the checksum is wrong

•

‘P’ & ‘CR’ & ‘LF’ if the Security is set

Flow Description: Blank

Check Command

Command Name

Record

Type

Load

Offset

Record

Length

Data[0]

Data[1]

Data[2]

Data[3]

Data[4]

Read Flash

04h

x

05h

start address

end Address

00h

Blank check on

Flash

01h

Read EEPROM

Data

02h

Host

Bootloader

Blank Check Command

’X’ & CR & LF

Flash blank

Wait Blank Check Command

Send first Address

Send COMMAND_OK

Send Blank Check Command

Wait Checksum Error

Wait Address not

erased

Wait COMMAND_OK

OR

COMMAND ABORTED

COMMAND FINISHED

Send Checksum error

COMMAND FINISHED

’.’ & CR & LF

OR

address & CR & LF

not erased

Checksum error