Flash Download Commands

Request Flash Identifier

Returns the size of the flash used. There may be 4, 8, or 16 sectors (64K each) in flash memory. The numbers returned are the number of sectors minus one (3, 7, or 15 respectively). This command assures that the firmware to be downloaded is the appropriate size for flash memory.

Hexadecimal

Decimal

ASCII

1D 01

29 1

GS SOH

Select Sector to Download

Selects the flash sector for which the next download operation applies.

The printer transmits ACK if the sector number is acceptable; NAK if unsuccessful.

Hexadecimal

Decimal

ASCII

Value of n

1D 02 n

29 2 n

GS STX n

00, 01*

 

 

 

(hexadecimal)

 

 

 

 

*Note: Send 00 or 01 only.

Request Retransmission of Last Response

Requests the printer to retransmit the last byte of the last response.

Hexadecimal

Decimal

ASCII

1D 05

29 5

GS ENQ

Check CRC

Causes the printer to calculate the CRC for the currently selected sector. This is performed normally after downloading a sector to verify that the downloaded firmware is correct. The printer also calculates the CRC for each sector during power up and halts the program if any sector is erroneous.

The printer transmits ACK if the calculated CRC is correct for the selected sector; NAK if the CRC is incorrect or if no sector is selected.

Hexadecimal

Decimal

ASCII

1D 06

29 6

GS ACK

10–4

3255 4073–002

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Unisys EFP9800 manual Flash Download Commands Request Flash Identifier, Select Sector to Download, Check CRC