MC33560
http://onsemi.com
12
DETAILED OPERATING DESCRIPTION
INTRODUCTION
The MC33560 smartcard interface IC has been designed
to provide all necessary functions for safe data transfers
between a microcontroller and a smartcard or memory card.
A card detector scans for the presence of a card and
generates
a
debounced
microcontroller.
Communication and control signal levels are translated
between the digital interface and the card interface by the
voltage level translator, and the card clock is matched to the
system clock frequency by the programmable card clock
wake–up
signal
to
the
generator. The power management unit enables the DC/DC
converter for card power supply, supervises the power
up/down sequence of the card’s I/O and signal lines, and
keeps the power consumption very low in stand by mode.
All card interface pins have adequate ESD protection, and
fault monitoring (VBATlow, VCClow, ICClim) guarantees
hazard–free card reader operation.
Several MC33560s can be operated in parallel, using the
same control and data bus, through the use of the chip select
signal
C
S.
Figure 21. MC33560 Operating Modes
STAND BY MODE
CS = H
PWRON = L
CS: RISING EDGE
ACTIVE MODE
CS = L
PWRON = L
CS: FALLING EDGE
ISO STOP SEQUENCE
IDLE MODE
CS = H
PWRON = H
ERROR
CONDITION
PROGRAMMING MODE
CS = L
RDYMOD = L
CS: 0 AND
PWRON: RISING EDGE
ISO START SEQUENCE
TRANSACTION MODE
CS = L
PWRON = H
PWRON: FALLING EDGE
OR ERROR CONDITION
PROGRAMMING MODE
CS = L
RDYMOD = L
CS: FALLING EDGE
RDYMOD: 0 AND
CS: 1 AND
RDYMOD: RISING EDGE
CS: 1 AND
RDYMOD: RISING EDGE
CS: FALLING EDGE
RDYMOD: 0 AND
OPERATING MODES
The MC33560 has five operating modes:
stand by
programming
active
transaction
idle
The transitions between these different states are shown in
figure 21 above.
STAND BY MODE
Stand by mode allows the MC33560 to detect card
insertion and monitor the power supply while keeping the
power consumption at a minimum. It is obtained with
CS=H
and
PWRON=L
.
When the MC33560 detects a card,
INT
is asserted low to
wake up the Microcontroller.
PROGRAMMING MODE
The programming mode allows the user to configure the
card Vcc
and the card clock signal for his specific
application. The card supply, CRDVcc, can be programmed
to 3V or 5V, and the card clock signal can be defined to be
either synchronous, or asynchronous divided by 1, 2 or 4.
Programming mode is obtained with
RDYMOD=L
followed by a negative transition on
CS
. The programming
options are shown in table 3. Programmed values are latched
on a positive transition of
CS
with
RDYMOD=L
.
ACTIVE MODE
In active mode, the MC33560 is selected, the
RDYMOD
pin becomes an output, and the MC33560 status can be
polled. Power is not applied to the card.
The microcontroller polls the MC33560 by asserting
CS=L
and reading the
RDYMOD
pin.
If a card is present, the microcontroller starts the DC/DC
converter by asserting
PWRON=H
. This starts the
automatic power on sequence: when CRDVcc
reaches the
undervoltage level (VT5H
or VT3H, depending on
programming), the card sequencer validates
CRDIO
,
CRDRST
,
CRDCLK
,
CRDC4
,
CRDC8
pins according to
the ISO7816–3 sequence (see figure 26). The MC33560 is
now in transaction mode, and the system is ready for data
exchange via the three I/O lines and the
RESET
line.
TRANSACTION MODE
In transaction mode, the MC33560 maintains power and
the selected clock signal applied to the card, and the levels
of the
IO
,
RESET
,
C4
and
C8
signals between the
microcontroller and the card are translated depending on the
supply voltages VBAT
and VCC.
The DC/DC converter status can be monitored on the
RDYMOD
pin.
IDLE MODE
Idle mode is used when maintaining a card powered up
without communicating with it. When an asynchronous
clock is used, the selected clock signal is applied to the card
POWER DOWN OPERATION
Power–down can be initiated by the controlling
microprocessor, by stopping the DC/DC converter with
PWRON=L
while
CS=L
, or by the MC33560 itself when
an error condition has been detected (CRDVcc
undervoltage,
overcurrent longer than 160ms typ., overtemperature, “hot”