srt512 STMicroelectronics, srt512 Datasheet - Page 12

• Manufacturer Part Number: srt512
• Description: 13.56 Mhz Short-range Contactless Memory Chip With 512-bit Eeprom And Anticollision Functions
• Manufacturer: STMicroelectronics

Data transfer
3.2.3
3.3
Figure 10. Example of a complete Transmission Frame
12/49
Sent by the
SRT512
Reader
Sent by
Answer End Of Frame
The EOF shown in
Figure 9.
Transmission Frame
Between the Request data transfer and the Answer data transfer, all ASK and BPSK
modulations are suspended for a minimum time of t
to switch from Transmission to Reception mode. It is repeated after each frame. After t
13.56 MHz carrier frequency is modulated by the SRT512 at 847 kHz for a period of
t
by the SRT512 forms the start bit (‘0’) of the Answer SOF. After the falling edge of the
Answer EOF, the reader waits a minimum time, t
the SRT512.
1
= 128/ƒ
SOF
at 106kb/s
12 bits
followed by 10 ETUs at logic-0,
followed by 2 ETUs at logic-1.
ETU
Cmd
S
Input data transfer using ASK
10 bits
to allow the reader to synchronize. After t
Answer End Of Frame
0
b0
Data
10 bits
t
DR
Figure 9
0
b1
CRC
10 bits
0
b2
CRC
10 bits
is composed of:
0
b3
EOF
10 bits
0
b4
128/fs
t
0
f s =847.5kHz
0
b5
Sync
128/fs
t
2
1
, before sending a new Request Frame to
Output data transfer using BPSK
0
b6
0
SOF
1
= 128/ƒ
12 bits
, the first phase transition generated
0
b7
Data CRC CRC
10 bits
S
. This delay allows the reader
0
b8
10 bits
10 bits
0
b9
EOF
t
12 bits
2
1
b10
Ai13506b
ai07665
SOF
1
b11
SRT512
0
, the