Unisys EFP9800 manual Flash Download Commands Erase Selected Sector, Download Sector

Flash Download Commands

Erase Selected Sector

Erases the sector that was selected previously.

The printer transmits ACK if the sector is erased successfully, NAK if no sector was selected previously.

Hexadecimal	Decimal	ASCII
1D 10 nn	29 16 nn	GS DLE nn

Download Sector

Contains a start address (ah*256 + al) and count (ch*256 + cl) of binary bytes to load into the selected sector, followed by that many data bytes. The start address is relative to the start of the sector.

Hexadecimal	Decimal		ASCII
1D 11 al ah cl ch d1 . . . dn	29 17 al ah cl ch d1 . . . dn		GS DC1 al ah cl ch d1 . . . dn
Value of n (for number of data bytes)		Range of Address (al ah)		Range of Count (cl ch)
((ch * 256) + cl)		2000-FFFF (hexadecimal)		0001-0400 (hexadecimal)

•al = low byte of the address (it is sent before the high byte)

•ah = high byte of the address (it is sent after the low byte)

•cl = low byte of the count (it is sent before the high byte)

•ch = high byte of the count (it is sent after the low byte)

•d = data bytes, from 1 to n

The printer may return one of the following responses:

•ACK means that the data was written correctly and the host should transmit the next block.

•NAK means that the data was not written correctly, either because communication failed or because the write to flash failed. The alternatives are to retry the block or halt loading and assume a hardware failure.

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