Rainbow-electronics AT89C5122 Manual do Utilizador descarregar pdf (Página 93)

AT8xC5122/23

4202E–SCR–06/06

advised to decrement the BOOST[1:0] bits to restore the overflow current to its normal

or desired value.

Monitoring Procedure Once the DC/DC has been successfuly initialized, it is necessary to monitor the DC/DC

converter by means of bits VCARDOK and ICARDOVF in the SCISR register.

Table 60. DC/DC converter status

VCARDOK ICARDOVF DC/DC Status

- Not Started or switched off by application.

The current overflow sensor is disabled during the DC/DC converter startup. Then if a current

overflow condition is applied during the DC/DC converter startup, the DC/DC converter is unable

to start and both bits VCARDOK and ICARDOVF remains at 0.

DC/DC converter correctly started then the output voltage is out of ISO/IEC 7816-3

specifications. In this case the firmware must take appropriate actions like deactivating the

DC/DC converter in compliance with ISO/IEC 7816.

0 1 Started and automatically switched off by a current overflow condition

1 0 Operating properly according to ISO/IEC 7816-3 and EMV recommendations

1 1 Not applicable

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Rainbow-electronics AT89C5122 Manual do Utilizador Página 93