73S8023C Maxim, 73S8023C Datasheet - Page 12

• Manufacturer Part Number: 73S8023C
• Description: The 73S8023C is a single smart card interface IC, compliant to the electrical requirements of ISO 7816-3, EMV 4
• Manufacturer: Maxim

73S8023C Data Sheet
8.3 Activation Sequence (Asynchronous Mode)
The 73S8023C smart card interface IC has an internal 10 ms delay at power-on reset or upon application
of V
high which indicates a card is present. No activation is allowed at this time. CMDVCC (edge triggered)
must then be set low to activate the card.
The following steps list the activation sequence and the timing of the card control signals when the
system controller sets CMDVCC low while the RSTIN is low:
1. CMDVCC is set low.
2. Next, the internal V
3. Turn I/O (AUX1, AUX2) to reception mode at the end of t
4. CLK is applied to the card at the end of t
5. RST is a copy of RSTIN after t
12
DD
the voltage V
low to report a fault to the system controller, and the power V
RST high until 42000 clock cycles after the start of CLK.
CMDVCC
t
STROBE
t
t
t
t
t
0
1
2
3
4
5
> V
- Deactivation starts after CMDVCC is set high or OFF falls due to card removal or fault
- RST falls approx. 0.5us after deactivation begins
- CLK falls approx. 7.5us after RST falls
- IO falls approx 2us after CLK falls
- VCC is shut down
- VCC goes to 0 after discharge of VCC capacitor, approx 100us after deactivation begins
RSTIN
(Note: Host should set STROBE low when CMDVCC is set high, otherwise CLK may be truncated.
CLK truncation may occur if an OFF event is triggered)
VCC
OFF
RST
CLK
DDF
IO
or upon exit of Power Down mode. The card interface may only be activated when OFF is
CC
Figure 4: Synchronous Deactivation Operation – CKSEL = High
to the card becomes valid during t
CC
control circuit checks the presence of V
4
. RSTIN may be set high before t
-- OR --
t
0
t
3
1
.
t
2
t
3
t
4
1
. If V
CC
2
.
does not become valid, then OFF goes
t
5
CC
CC
to the card is turned off.
at the end of t
4
, however the sequencer won’t set
1
. In normal operation,
DS_8023C_019
Rev. 1.5