| 摘要 |
A data processing device 10 and method of use, comprising a processor 20 and a memory interface 24, the processor 20 being configured to control the refreshing of a memory 12 , which may be non volatile , (e.g flash) by the steps of: periodically forming an estimate of a current rate of decay of a memory and updating an accumulated level of decay of the memory in dependence on the estimated current rate of decay, preferably in dependence of temperature; and causing the memory interface to refresh the memory (figure 3) when the accumulated level of decay exceeds a predetermined threshold (figure 4) . The estimate may be based on a measurement of ambient temperature. A temperature sensor 22 incorporating a bandgap temperature reference circuit 30, which may also be included on the same integrated substrate 11 as the data processing device 20. The processor 20 may save on power consumption by only periodically activating the temperature sensor 22. The processor may comprise a model of the rate of decay of the memory as a function of the temperature, and hence use this as the basis of an estimate of the current rate of decay. The data processing device may further comprise a wireless (RF) transceiver, antenna, memory and an environmental sensor for sensing a parameter other than temperature and a battery for powering the sensing device. The data processing device may be comprised within an environmental sensing device such as tyre pressure sensor (figure 1) for an automobile or road vehicle and whereby the memory and battery are sealed within a housing. |
