73S8024RN Data Sheet
DS_8024RN_020
MICROCONTROLLER INTERFACE
Name
Pin
Pin
Pin
Description
28SO
20QFN 32QFN
CMDVCC
19
10
20
18
Command VCC (negative assertion): Logic low on this pin
causes the LDO regulator to ramp the VCC supply to the
card and initiates a card activation sequence, if a card is
present.
5V/#V
3
31
5 volt / 3 volt card selection: Logic one selects 5 volts for
VCC and card interface, logic low selects 3 volt operation.
When the part is to be used with a single card voltage,
this pin should be tied to either GND or VDD. However, it
includes a high impedance pull-up resistor to default this
pin high (selection of 5V card) when not connected.
CLKSTOP
CLKLVL
7
8
–
–
4
5
Stops the card clock signal during a card session when
set high (card clock STOP mode). Internal pull-down
resistor allows this pin to be left as an open circuit if the
clock STOP mode is not used.
Sets the logic level of the card clock STOP mode when
the clock is de-activated by setting pin 7 high. Logic low
selects card STOP low. Logic high selects card STOP
high. Internal pull-down resistor allows this pin to be left
as an open circuit if the clock STOP mode is not used.
CLKDIV1
CLKDIV2
1
2
18
19
29
30
Sets the divide ratio from the XTAL oscillator (or external
clock input) to the card clock. These pins include
pull-down resistors.
CLKDIV1
CLKDIV2
CLOCK RATE
XTALIN/8
XTALIN/4
XTALIN/2
XTALIN
0
0
1
1
0
1
1
0
OFF
23
14
22
Interrupt signal to the processor. Active Low - Multi-
function indicating fault conditions and card presence.
Open drain output configuration. It includes an internal
21kΩ pull-up to VDD.
RSTIN
I/OUC
20
26
11
17
19
26
Reset Input: This signal is the reset command to the card.
System controller data I/O to/from the card. Includes a
pull-up resistor to VDD.
AUX1UC
AUX2UC
27
28
–
–
27
28
System controller auxiliary data I/O to/from the card.
Includes a pull-up resistor to VDD.
System controller auxiliary data I/O to/from the card.
Includes a pull-up resistor to VDD.
6
Rev. 1.8