TCA5013 Datasheet, PDF (27/68 Pages) Texas Instruments – Feature Rich Smartcard Interface IC

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TCA5013
SCPS253B – JANUARY 2014 – REVISED JANUARY 2016
inserted in the slot the PRES pin shall be high. The status of the PRES_UC bit is based on the status of the
PRES pin and the CARD_DETECT_UC bit. The truth table in Table 1 shows the PRES_UC bit status based on
the CARD_DETECT_UC bit and the PRES pin. When coming out of power off mode (see Power Off Mode) or
shutdown mode (see Shutdown Mode) the CARD_DETECT_UC = 0. If there is a state transition on the PRES
pin when the device is in shutdown mode, the INT pin asserted (after the 20 ms debounce).
Table 5. Truth Table Defining Status of PRES Bit
CARD DETECT BIT
0
0
1
1
PRES PIN
0
1
0
1
PRES BIT
1
0
0
1
Figure 9 to Figure 14 show timing waveforms of device power up and coming out of shutdown with and without a
card inserted in the system. In below figures’ low to high PRES topology’ means that a high level on the PRES
pin indicates a card is present. In below figures high to low PRES topology’ means that a low level on the PRES
pin indicates a card is present. The below figures also show operation of INT pin and interrupt status register. For
detailed description of the interrupt operation, refer to Interrupt Operation section.
SHDN
Debounce period
20ms
SHDN
released
by µC
(pull-up)
Power on Reset
PRES
INT
2
IC
Card insertion /
extraction
POR interrupt
PRES bit =0
PRES bit = 1
Interrupt
status
register
read
CARD
DETECT =1
Figure 9. Card detection in shutdown mode - Low to High PRES Topology
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