Maxim Integrated 73S12xxF - Manual (Page 23)

UG_12xxF_018 Using Synchronous Smart Cards with the 73S12xxF
Rev. 1.0 23
WAITTO bit
set?
Last byte of
ATR received?
C
Wait for smart card Interrupt
Read SCInt
Read SRXData and store in
ATR buffer
Yes
No
No
Yes
Complete ATR received (4th byte)?
Wait timeout is used for RLEN count
reached indication.
Set RLEN to 8
END
Disable smart card
interrupts. SCIE = 0
Turn off CLK high and set
I/O for input high,
set CLKOFF, CLKLVL, IO
and IOD bits in SCCtl
Figure 25: 2-Wire Card Activation and ATR Retrieval Flowchart