DS8007 Maxim, DS8007 Datasheet - Page 35

• 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

The ISO UART is designed to support two possible char-
acter encoding/decoding formats: direct and inverted.
The direct character coding convention transmits and
receives data LSb first and associates a high logic level
with a bit 1 and a low logic level with a bit 0. The inverse
character coding convention transmits and receives data
most significant bit first and associates a high logic level
with a bit 0 and a low logic level with a bit 1.
The UCR1.CONV bit defines which character conven-
tion (CONV = 0:inverse; CONV = 1:direct) should be
used by the ISO UART. The UCR1.CONV bit can be
configured by the host device software or be config-
ured by hardware if automatic convention detection has
been enabled.
The automatic convention detection relies upon recog-
nition of a predefined pattern in the first character
received (TS character) in ATR for establishing future
character coding convention. To enable automatic con-
vention detection, the UCR1.SS bit must be set to logic
1 and the UCR2.AUTOC bit should be configured to
logic 0 prior to ATR. The SS bit is automatically cleared
by hardware 10.5 ETU after the character is received. If
automatic convention detection is enabled and an
unrecognized character is received, the CONV bit is
not written. If neither the direct nor inverse character
are detected, a parity error occurs along with error sig-
nal generation for the T = 0 protocol. The AUTOC bit
should not be modified during a card session.
The DS8007 monitors the selected card I/Ox signal at
10.25 ETU following each detected start bit. If the I/Ox
signal is not in the high state at this point in time, the
USR.FER (framing error) bit is set to 1 at 10.5 ETU. The
FER bit is cleared to 0 whenever USR is read.
Automatic Convention Detection
______________________________________________________________________________________
Multiprotocol Dual Smart Card Interface
Framing Error Detection
Decoding Convention
Character Encoding/
Figure 12. Direct, Inverse Character Coding Conventions
Figure 13. ISO UART Signal Interface
I/OA
I/OB
I/OAUX
f
2 x f
START DETECT
ETU
INVERSE CONVENTION (BYTE = 3Fh)
CLKx
MSb
LSb
(CONVEYS CODING CONVENTION)
DIRECT CONVENTION (BYTE = 3Bh)
1
0
CLKx
1
0
ISO UART
FIFO(8)
TS CHARACTER
0
1
URR
UTR
1
1
1
1
1
1
0
1
USR.EA
USR.PE
FCR.FL[2:0]
PDR.PD[7:0]
GTR.GTR.[7:0]
UCR1
UCR2
CSR.RIU
MSR.FE
MSR.BGT
MSR.TBE/RBF
USR.OVR
USR.FER
FCR.PEC[2:0]
MSb
0
1
LSb
1
0
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