A method for data transmission from a programming device to a control unit, the data being compressed by Huffman coding and transmitted with a Huffman coding tree for decoding from the programming device to the control unit, are decompressed and stored in the control unit, by performing, for a predetermined number of data words of N-bits, a first Huffman coding with a first coding tree; performing, for the remaining data words consisting of M-bits, a second Huffman coding with a second coding tree, N greater than M, the predetermined number of data words of N-bits and the remaining data words of M-bits consisting of more than two data words, generating coding trees for the N-bit and the M-bit data words, and transmitting them to the control unit, and providing all coded N-bit data words and N / M of successive M-bit data words with a preceding code bit.