TCA5013 Datasheet, PDF (26/68 Pages) Texas Instruments – Feature Rich Smartcard Interface IC

TCA5013
SCPS253B – JANUARY 2014 – REVISED JANUARY 2016
Rising edge of SCL
corresponding to ACK
I ²C
SCL
< 5μs
RST
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t
DEAC-TOT
t
DEAC-RST-CLK
+
two
card
clock
cycles
CLK
t _DEAC-RST-IO
IO
t _DEAC-RST-VCC
VCC
<0 .4 V
Figure 8. Card Deactivation Sequence Initiated by I²C Command
Table 4. Card Deactivation Timing Characteristics
t_DEAC-TOT
t_DEAC-RST-CLK
t_DEAC-RST-IO
t_DEAC-RST-VCC
MIN
TYP
MAX
UNIT
0.4
0.5
0.6
ms
10
12
15
µs
22
24
26
µs
33
36
39
µs
8.4.5 User Card Insertion / Removal Detection
User card interface module in the TCA5013 has a PRES pin that is used to detect the presence of a card in that
interface. In normal application the signal is connected to a switch that opens or closes when a card is inserted.
Whenever a transition is seen on the PRES pin, the PRESL bit (Reg 0x00, bit 2) will be set and INT pin is
asserted. Because this transition is associated with a mechanical switch, there is an internal debounce of ~20 ms
before the PRESL bit is set and the INT is asserted. If the device sees a transition on the PRESL pin when the
card interface is active, the device initiates a card deactivation sequence (see Deactivation Sequence). TCA5013
is capable of detecting card insertion even when it is in shutdown mode (see Shutdown Mode).
In addition to the PRESL_UC bit mentioned above, there is also a PRES_UC bit (Reg 0x00, bit 2), which
indicates to the host whether or not a card is present in the user card slot. In order to accommodate different
card cage topologies, the TCA5013 can be configured to detect card presence with a low to high or high to low,
transition on the PRES pin. The CARD_DETECT_UC bit (Reg 0x01, bit 2) is used to configure the device for
different card detection topologies. If CARD_DETECT_UC = 0 indicates to the TCA5013 that when a card is
inserted in the slot, the PRES pin shall be low. CARD_DETECT_UC = 1 indicates to the host that when a card is
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