DS8007 Maxim, DS8007 Datasheet - Page 28

• Manufacturer Part Number: DS8007
• Description: The DS8007 multiprotocol dual smart card interface is a low-cost, dual smart card reader interface supporting all ISO 7816, EMV®, and GSM11-11 requirements
• Manufacturer: Maxim

Multiprotocol Dual Smart Card Interface
An activation sequence can only be requested by a
host device through the parallel bus interface. The host
can request an activation sequence for a specific card
(card A or card B) by setting the START bit of the PCRx
register (where x = A or B as determined by the card
select SCx bits of the CSR). The host software can acti-
vate both cards at the same time, but only one card
can be selected to transmit/receive at a given time. The
activation sequence can only occur given satisfactory
Figure 9. Card Activation, Deactivation Sequences
28
ACTIVATION SEQUENCE
1. PCRx.START BIT IS SET BY SOFTWARE.
2. STEP-UP CONVERTER ACTIVATED (MAY ALREADY BE ON IF ANOTHER CARD WAS ACTIVE).
3. V
4. I/Ox IS PULLED HIGH. C4x, C8x ARE ALSO PULLED HIGH IF PCRx.C4 = 1, PCRx.C8 = 1
5. CLKx OUTPUT IS ENABLED AND RST OUTPUT IS ENABLED.
6. PCRx.RSTIN WRITTEN TO "1" BY SOFTWARE AFTER USING TOC TO TIME SUFFICIENT
START BIT
RSTIN BIT
C4x, C8x
CONDITIONS NEEDED (IN HARDWARE) ARE:
V
(RESPECTIVELY). THESE PINS HAVE INTEGRATED PULLUPS (14kΩ FOR I/Ox AND
10kΩ FOR C4x AND C8x) TO V
(PCRx.RSTIN SHOULD BE "0" FOR ACTIVE-LOW RSTx.)
DURATION OF RSTx PIN ASSERTION.
TIMING
CCx
CCx
______________________________________________________________________________________
MSR.PRx = 1 (CARD x PRESENT)
HSR.PRTLx, SUPL, PRLx, PTL = 0
RSTx
CLKx
V
V
I/0x
CCx
ENABLED TO 1.8V, 3V, OR 5V AS SELECTED BY PCRx.1V8 AND PCR.3V/5V BITS.
RISES FROM 0V TO 1.8V, 3V, OR 5V WITH A CONTROLLED RISE TIME OF 0.17V/μs TYPICAL.
UP
t0
1
2
t1
ACTIVATION SEQUENCE
Activation Sequencing
CCx
t2
t
3
ACT
.
t3
4
UNDEFINED
t4
5
ACTIVATION NEEDS TO OCCUR IN UNDER 130μs
t5
6
ACCORDING TO PCRx.C4, PCRx.C8 BITS
V
TS
CCx
NEEDS TO DECREASE TO LESS THAN 0.4V
T0
operating conditions (e.g., the card is present and the
supply voltage is correct). These conditions can be
ascertained through the HSR, MSR, and CSR bits.
If the microcontroller attempts to write the PCRx.START
bit to 1 without having satisfied the necessary condi-
tions, the card is not activated and the bit does not
change. The activation time (from the assertion of the
START bit until the clock output is enabled) is less than
130µs. The activation sequence is detailed in Figure 9.
DEACTIVATION SEQUENCE
1. PCRx.START BIT IS CLEARED BY SOFTWARE.
2. THE ACTIVE-LOW RSTx SIGNAL IS ASSERTED BY SOFTWARE.
3. THE CLKx SIGNAL IS STOPPED.
4. I/Ox, C4x, AND C8x FALL TO 0V.
5. V
6. STEP-UP CONVERTER IS DEACTIVATED IF NOT IN USE BY ANOTHER CARD AND
PINS CLKx, RSTx, I/Ox, AND V
CCx
IS DISABLED AND FALLS TO 0V WITH A TYPICAL RATE OF 0.17V/μs.
t10
1
t11
2
CCx
DEACTIVATION SEQUENCE
t12
BECOME LOW IMPEDANCE TO GROUND.
3
t
DE
t13
4
t14
5
t15
6