| 摘要 |
A card 2 having a memory microcircuit 20 with access controlled by hard-wired logic to the microprocessor 21 may interact with a terminal 1. The memory, in epROM (or e<2>pROM) technology, includes value words (for example, of thirty-two bits, of which twenty-five are value bits, four bits serve to code the value unit allocated to each of these bits, and a validation bit). By loading the memory with a plurality of words possessing the series of value units graded according to the successive powers of 2, calculating means may simply break down any transaction amount below the maximum value of the card into binary form, by consuming, for each transaction, at most one single bit for the value units, except possibly the highest. <IMAGE> |
