sri512 STMicroelectronics, sri512 Datasheet - Page 12

• Manufacturer Part Number: sri512
• Description: 13.56-mhz Short-range Contactless Memory Chip With 512-bit Eeprom And Anti-collision Functions
• Manufacturer: STMicroelectronics

Data transfer
3.2.3
3.3
12/50
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 SRI512 at 847 kHz for a period of
t
by the SRI512 forms the start bit (‘0’) of the Answer SOF. After the falling edge of the Answer
EOF, the reader waits a minimum time, t
SRI512.
Figure 10. Example of a complete Transmission Frame
1
Sent by the
Sent by the
= 128/ƒ
Reader
SRI512
followed by 10 ETUs at logic-0,
followed by 2 ETUs at logic-1.
ETU
S
SOF
to allow the reader to synchronize. After t
at 106kb/s
12 bits
Answer End Of Frame
0
b0
Cmd
Input data transfer using ASK
10 bits
Figure 9
0
b1
Data
10 bits
t
DR
0
b2
is composed of:
CRC
10 bits
0
b3
CRC
10 bits
0
b4
EOF
2
10 bits
, before sending a new Request Frame to the
0
b5
128/fs
t
0
f s =847.5kHz
0
b6
0
1
128/fs
= 128/ƒ
Sync
, the first phase transition generated
t
1
Output data transfer using BPSK
0
b7
SOF
12 bits
S
. This delay allows the reader
0
b8
Data CRC CRC
10 bits
10 bits
0
b9
10 bits
1
b10
EOF
t
12 bits
2
ai07665
Ai10798
1
b11
SRI512
SOF
0
, the