AT89C5131A(2004) View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT89C5131A
(Rev.:2004)

USB Microcontrollers

Atmel Corporation 

Answers from the Device to a

Blank Check Command

Programming

Configuration

Information

Request from Host

The Host controller send a GET_STATUS request to the device. Once internal blank

check has been completed, the device sends its status.

• If the device status is “OK”:

the device memory is then blank and the device waits the next Host request.

• If the device status is “errCHECK_ERASED”:

the device memory is not blank. The device waits for an DFU_UPLOAD request to

send the first address where the byte is not 0xFF.

The flow described below allows the user to program Configuration Information regard-

ing the bootloader functionality.

• Boot Process Configuration:

– BSB

– SBV

– P1_CF, P3_CF and P4_CF

– Fuse bits (BLJB, X2 and OSCON bits) (see section “Mapping and Default

Value of Hardware Security Byte”)

Take care that the Program Fuse bit command programs the 4 Fuse bits at the same

time.

To start the programming operation, the Host sends DFU_DNLOAD request with the

Write command in the data field (6 bytes).

SETUP

DFU_DNLOAD

OUT

IN

Write_command (6 bytes)

ZLP

Answers From Bootloader

Command

Identifier

data[0]

01h

Id_write_command

04h

02h

data[1]

00h

01h

02h

03h

04h

05h

06h

00h

data[2]

Value

Value

data[3]

data[4]

Description

Write value in BSB

Write value in SBV

Write P1_CF

Write P3_CF

Write P4_CF

Write value in SSB

Write value in EB

Write value in Fuse

(HSB)

The device has two possible answers to a DFU_GETSTATUS request:

• If the chip is protected from program access, a “err_WRITE” status is returned to the

Host.

• Otherwise, the device status is “OK“.

20 AT89C5131A USB Bootloader

4287C–USB–11/04

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