MC33560
http://onsemi.com
13
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:
Standby
Programming
Active
Transaction
Idle
The transitions between these different states are shown in
STANDBY MODE
Standby 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 3 V or 5 V, 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 DCDC
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 ISO78163 sequence (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 I/O, RESET, C4 and C8 signals between the
microcontroller and the card are translated depending on the
supply voltages VBAT and VCC.
The DCDC 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.
POWERDOWN OPERATION
Powerdown
can
be
initiated
by
the
controlling
microprocessor, by stopping the DCDC converter with
PWRON = L while CS = L, or by the MC33560 itself when
an
error
condition
has
been
detected
(CRDVCC
undervoltage, overcurrent longer than 160 ms typ.,
overtemperature,
“hot”
card
extraction).
The
communication session is terminated in a given sequence
defined in ISO78163.
The MC33560 then goes into active mode, in which its
status can be polled.
Standby mode is reached by deselecting the MC33560
(
CS = H).
FUNCTIONAL BLOCKS
CARD DETECTOR
This block monitors the card contact CRDDET (during
insertion and extraction), filters the incoming waveform and
generates an interrupt signal INT after each change. In order
to identify which coupler activated the INT line
(multicoupler application) the microcontroller scans both
circuits via CS and reads the RDYMOD pin.
The programming input CRDCON tells the level detector
which type of mechanical contact is implemented (normally
open or normally closed). Special care is taken to hold the
current consumption very low on this part of the circuit
which is continuously powered by the VBAT supply.
The CRDDET pin has high impedance input, and an
external resistor must be connected to pullup or pulldown,
depending on CRDCON. This resistor is chosen according to
the maximum leakage current of the card connector and the
PCB.