Rainbow-electronics DS8314 Manuel d'utilisateur télécharger pdf (Page 14)

DS8313/DS8314

Stop Mode (Low-Power Mode)

A low-power state, stop mode, can be entered by forc-

ing the CMDVCC, 5V/3V, and 1_8V input pins to a

logic-high state. Stop mode can only be entered when

the smart card interface is inactive. In stop mode, all

internal analog circuits are disabled. The OFF pin fol-

lows the status of the PRES pin. To exit stop mode,

change the state of one or more of the three control

pins to a logic-low. An internal 220µs (typ) power-up

delay and the 8ms PRES debounce delay are in effect

and OFF is asserted to allow the internal circuitry to sta-

bilize. This prevents smart card access from occurring

after leaving the stop mode. Figure 8 shows the control

sequence for entering and exiting stop mode. Note that

an in-progress deactivation sequence always finishes

before the DS8313/DS8314 enter low-power stop

mode.

Smart Card Interface

14 ______________________________________________________________________________________

CMDVCC

1_8V

5V/3V

STOP MODE

OFF

PRES

DEACTIVATE INTERFACE

ACTIVATE

STOP MODE

DEACTIVATE

STOP MODE

220μs DELAY

OFF FOLLOWS

PRES IN STOP MODE

OFF ASSERTED TO

WAIT FOR DELAY

8ms DEBOUNCE

Figure 8. Stop-Mode Sequence

1 2 ... 9 10 11 12 13 14 15 16 17

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Rainbow-electronics DS8314 Manuel d'utilisateur Page 14