| 摘要 |
<p>The device for altering a control programme in a processor (1) is of the type in which the processor executes a control programme stored in a permanent memory (2) and has access to a number of altering routines (221 to 22M). Each routine is designed to be executed in the place of a train of at least one instruction of the control programme. The device includes a store for a number of rerouting addresses, each associated with the address of one of the altering routines. A comparator (31) for checks the address of the control programme contained in the computer programme (32) with the rerouting addresses contained in the memory. The control programme is re-routed in the case of positive comparison by the comparator (31), towards the altering routine whose address is associated with the altering address having made it the object of the positive comparison. Each altering address is also associated with one of the possible operating states of the processor. The device also includes an address selector from a pre-determined number of altering addresses, among those stored in the memory (40), so that the altering addresses selected are those associated with the current operating state of the processor. The address contained in the computer programme is uniquely compared with the selected altering addresses.</p> |
