PCF7936AS/3851/C,1-CT NXP Semiconductors, PCF7936AS/3851/C,1-CT Datasheet - Page 11

• Manufacturer Part Number: PCF7936AS/3851/C,1-CT
• Description: pcf7936as series 32-bit 125 khz read / write security...
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Security Transponder (HITAG2)
7.2 Transponder State Diagram
Device operation is controlled by commands issued from
the basestation, see Figure 7.
After a LF Field Power-On Reset condition the circuitry is
reset and the transponder is initialized, which causes the
device to enter the WAIT state.
If one of the Read Only modes is enabled, the device will
enter READ ONLY state after the specified time-out
(t
To authenticate the transponder and to access the
Transponder Memory for read and write the AUTHORIZED
state has to be entered, by means of a START_AUTH
command and successful completion of the authentication
sequence. Subsequent memory read and write operations
may be executed.
Operation of the transponder commands depend on the
device configuration (Password or Cipher Mode).
If the device is forced into HALT state, by means of the
HALT command, the transponder circuitry is muted.
A violation of the command sequence coding or command
timing in any state causes an error condition, which causes
the device to enter WAIT state and to reset the time-out
(t
2010 May 04
WAIT,SA
WAIT,SA
Figure 7. Transponder State Diagram
), if no command is being issued.
).
READ ONLY
READ_PAGE_INV
WRITE_PAGE
READ_PAGE
Read Only = enabled
time-out (t
&
WAIT,SA
Error
)
AUTHORIZED
WAIT
11
START_AUTH
Power On Reset
7.2.1 WAIT State
In WAIT state general memory access is denied.
Commands may be issued to start device authentication, in
order to enter the AUTHORIZED state, see Table 2.
Table 2. Command Set in WAIT State
NAME
Reserved
Reserved
Reserved
Reserved
Reserved
START_AUTH
Note
1. This command is reserved for future use and subject to
Upon entering the WAIT state the time-out (t
reset. In case t
enters READ ONLY state, if one of the Read Only modes is
enabled. In case a START_AUTH command is issued,
device authentication is triggered and the READ ONLY
state is not entered. At least the first two bits of
START_AUTH need to be recognized by the device within
the time-out period specified by t
LF Field
change without notice. The actual implementation
causes the device to generate an error condition and to
enter the WAIT state, if this command is being issued.
HALT
1)
1)
1)
1)
1)
WAIT,SA
is allowed to time-out, the device
CM4 CM3 CM2 CM1 CM0
HALT
0
X
X
X
X
1
COMMAND, CMD
WAIT,SA
X
X
X
X
0
1
Product Specification
.
PCF7936AS
X
X
X
X
1
0
CONFIDENTIAL
X
X
X
X
1
0
WAIT,SA
X
X
X
X
0
1
) is