ModemModule Developer’s Guide

Program Sequence

 

 

DTE

Modem

Comments

ATFLP\r

 

Request to the modem to program

 

G

Modem is ready for next program packet

[Length High]

 

High byte of data packet length

[Length Low]

 

Low byte of data packet length

 

 

Packet lengths can be up to 4096 bytes in size for

 

 

most boot code versions (see section 3.5)

[Address High]

 

High byte of program address

[Address Middle]

 

Middle byte of program address

[Address Low]

 

Low byte of program address

 

 

Addresses are 3 byte values with a range of

 

 

00000h-FFFFFh (see sections 3.2 - 3.4)

[Data Bytes]

 

These are the data bytes to be programmed at the

 

 

address specified above. They must be the same

 

 

number of bytes as specified above.

 

 

(see section 3.1)

[Checksum

 

This checksum is generated by exclusive ORing

 

 

together all of the Data Bytes (do not include the

 

 

Length or Address bytes in that calculation).

 

\nOK\r\n

If bytes are programmed and verified.

 

\nERROR\r\n

If verify fails or checksum is bad.

 

 

Retry the block 3 times on an ERROR.

....

....

More of the above sequence until all the data bytes

 

 

have been sent to the modem.

ATFLEND\r

 

This ends programming and restarts the modem

2.Other supported boot code commands

2.1.ATI0 - returns 247

2.2.ATI1 - returns boot code version number MM.mm where

MM= unique code for each different platform that has boot code mm = version number of boot code

2.3.AT*FI - when given in standard AT mode gives the boot code version (same as in section 2.2). See section 3.7.

3.Other programming concerns

3.1.The values programmed into Addresses 0000h, 0001h and 0002h should always be forced to C3h 01h 00h (ie. JP 100h).

This is because the boot code starts at address 100h, while all normal modem code starts at 200h. By allowing 0000h to be programmed to a jump value other than 0100h, the boot code would be bypassed and no further upgrades could occur.

3.2.Addresses 1E0000h through 1FFFFh should not be allowed to be programmed under normal circumstances as this is the main body of the boot up code.

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MT3334SMI

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Multi-Tech Systems MT3334SMI manual Other supported boot code commands, Other programming concerns