Rainbow Electronics MAX66000 User Manual

Page 6

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MAX66000

ISO/IEC 14443 Block

Transmission Protocol

Before the master can send a data packet to access the
memory, the MAX66000 must be in the ACTIVE state.
The protocol to put the MAX66000 into the ACTIVE state
is explained in the

Network Function Commands

sec-

tion. While in the ACTIVE state, the communication
between the master and the MAX66000 follows the
block transmission protocol as specified in Section 7 of
ISO/IEC 14443-4. Such a block (Figure 10) consists of
three parts: the prologue field, the information field, and
the epilogue field. The prologue can contain up to 3
bytes, called the protocol control byte (PCB), card iden-
tifier (CID), and the node address (NAD). Epilogue is
another name for the 16-bit CRC that precedes the EOF.
The information field is the general location for data.

Block Types

The standard defines three types of blocks: I-block,
R-block, and S-block. Figures 11, 12, and 13 show the
applicable PCB bit assignments.

The I-block is the main tool to access the memory. For
I-blocks, bit 2 must be 1 and bit 6 to bit 8 must be 0. Bit
5, marked as CH, is used to indicate chaining, a func-
tion that is not used or supported by the MAX66000.
Therefore, bit 5 must always be 0. Bit 4, marked as CID,

is used by the master to indicate whether the prologue
field contains a CID byte. The MAX66000 processes
blocks with and without CID as defined in the standard.
The master must include the CID byte if bit 4 is 1. Bit 3,
marked as NAD, is used to indicate whether the pro-
logue field contains an NAD byte, a feature not support-
ed by the MAX66000. Therefore, bit 3 must always be
0. Bit 1, marked as #, is the block number field. The
block number is used to ensure that the response
received relates to the request sent. This function is
important in the error handling, which is illustrated in
Annex B of ISO/IEC 14443-4. The rules that govern the
numbering and handling of blocks are found in
Sections 7.5.3 and 7.5.4 of ISO/IEC 14443-4. The
MAX66000 ignores I-blocks that have bit 5 or bit 3 set
to 1.

For R-blocks, the states of bit 2, bit 3, bit 6, bit 7, and
bit 8 are fixed and must be transmitted as shown in
Figure 12. The function of bit 1 (block number) and bit 4
(CID indicator) is the same as for I-blocks. Bit 5,
marked as AN, is used to acknowledge (if transmitted
as 0) or not to acknowledge (if transmitted as 1) the
reception of the last frame for recovery from certain
error conditions. The MAX66000 fully supports the func-
tion of the R-block as defined in the standard. For
details and the applicable rules, refer to Sections 7.5.3
and 7.5.4 and Annex B of ISO/IEC 14443-4.

ISO/IEC 14443 Type B-Compliant
64-Bit UID

_______________________________________________________________________________________

PROLOGUE FIELD

INFORMATION FIELD

EPILOGUE FIELD

PCB

CID NAD

(DATA)

CRC

(LSB)

CRC

(MSB)

1 BYTE

0 OR MORE BYTES

1 BYTE

Figure 10. ISO/IEC 14443-4 Type B Block Format

BIT 8

BIT 7

BIT 6

BIT 5

BIT 4

BIT 3

BIT 2

BIT 1

MSb

LSb

CID

NAD

Figure 11. Bit Assignments for I-Block PCB