ATR Editor — ISO/IEC 7816-3

Answer-to-Reset Editor

Edit ATR byte sequences interactively. Paste or type a hex string above and the field editors will update automatically — or edit individual fields and watch the hex string rebuild with live TCK checksum recalculation.

ATR Hex

2 bytes

Annotated bytes

TS3B

T000

Valid ATR2 bytes

Interface Bytes

TSInitial Character — Convention

3B— Direct convention

State H encodes bit 1, LSB transmitted first.

3F— Inverse convention

State L encodes bit 1, MSB transmitted first.

TA1Clock Rate / Baud Rate Parameters

TB1Deprecated Global Byte

deprecated

Raw value (hex)

Binary00000000b

TC1Extra Guard Time

N (extra guard time) — 0-255

Hex value

Dec

No extra guard time (default)

TD1Structural Byte — Protocol Chain

Historical Bytes

T1–T1Historical Bytes (K=0)

Optional bytes T1-TK describing card operating characteristics (K=0-15, encoded in T0 bits 4-1). Structure defined by ISO/IEC 7816-4.

0/15

No historical bytes (K=0)

Check Byte

TCK

Not required (T=0 only)