st8024l STMicroelectronics, st8024l Datasheet - Page 19

• Manufacturer Part Number: st8024l
• Description: Smartcard Interface
• Manufacturer: STMicroelectronics

ST8024L
5.6
Note:
Activation sequence
After power-on and after the internal pulse width delay, the system microcontroller can
check the presence of a card using the signals OFF and CMDVCC as shown in
If the card is in the reader (this is the case if PRES or PRES is active), the system
microcontroller can start a card session by pulling CMDVCC low. The following sequence
then occurs (see
The clock may be applied to the card using the following sequence (see
If the applied clock is not needed, then CMDVCC may be set low with RSTIN low. In this
case, CLK will start at t
may be set high in order to obtain an Answer To Request (ATR) from the card.
Activation should not be performed with RSTIN held permanently high.
It is recommended that no control smartcard signals are to be shared with any other
devices. Sharing could result in inadvertent activation or deactivation of the smartcard.
Table 22.
1. CMDVCC is pulled low and the internal oscillator changes to its high frequency (t
2. The step-up converter is started (between t
3. V
T is 64 times the period of the internal oscillator (approximately 25 µs).
4. I/O, AUX1 and AUX2 are enabled (t
moment).
5. CLK is applied to the C3 contact of the card reader (t
6. RST is enabled (t
1. Set RSTIN high.
2. Set CMDVCC low.
3. Reset RSTIN low between t
4. RST remains low until t
5. After t
pulses before toggling RST.
CC
rises from 0 to 5 V (or 1.8 V, 3 V) with a controlled slope (t
Card presence indicator
OFF
5
, RSTIN has no further affect on CLK; this allows a precise count of CLK
H
L
Figure
3
6):
5
(minimum 200 ns after the transition on I/O), and after t
= t
1
Doc ID 17709 Rev 3
+ 7T).
5
, when RST is enabled to be the copy of RSTIN.
3
and t
CMDVCC
5
3
; CLK will start at this moment.
= t
H
H
1
+ 4T) (these were pulled low until this
0
and t
1
).
4
).
Functional description
card not present
2
card present
= t
Indication
Figure
1
+ 1.5 x T) where
5):
Table
5
, RSTIN
22.
19/33
0
).