| 摘要 |
<p>A fault tolerant smart card (10) is provided having primary functional units including a standard ISO interface (12), a first microcontroller (14), a clock (22, 26), and main memory (16, 18, 20). Secondary functional units including a secondary microcontroller (30), secondary memory (32) with bit checking capability (34) and an alternate battery power source (28) are also provided. A microcontroller error detector (36) is connected to both microcontrollers (14, 30). Should a discrepancy between microcontrollers (14, 30) occur known test patterns are run on the second microcontroller (30) to determine which microcontroller is faulty. A private access port (44) provides alternate access to information stored in the fault tolerant smart card (10). Registers for funds remaining (38), error condition (42) and access account (40) are also provided.</p> |
