Electronic Components Datasheet Search |
|
EM4169A5WT11 Datasheet(PDF) 10 Page - EM Microelectronic - MARIN SA |
|
EM4169A5WT11 Datasheet(HTML) 10 Page - EM Microelectronic - MARIN SA |
10 / 15 page EM4069 EM4169 Copyright 2003, EM Microelectronic-Marin SA 10 www.emmicroelectronic.com Modulation of Magnetic Field The modulation envelope of the magnetic field induced by the reader is observed by the EM4069 as shown in the following figure. Synchronization pattern SB B0 B1 B2 B3 B4 B5 B6 B7 tS1 tS2 tS3 tRDB Fig. 12 Comment to above timings: tS1 : at least 4 samples of peak detector have to be HIGH. In worst case the distance between samples can be 2 bit periods. tS2 : at least one sample LOW. 2 bit periods + some security since the IC and R/W unit are not synchronized. Duration of 3 bit periods is suggested. tS3 : one sample high to enter Command Processing state defines lower limit. Watchdog timer defines higher limit (8 bits periods) Please note that during this time the Modulator load is permanently on so this is the worst case for Power Supply level. So using shorter times than upper limit is advised. Duration of 3 bit periods is suggested. Refer to table 4 for timings range. In the above example, the Read ROM command (1010 0101) is sent. After successful 8-bit command detection, the EM4069 will output continuously the ROM contents . Reset, Read ROM and Read Configuration Word commands After detecting these commands the IC returns in read mode and starts reading corresponding block (EEPROM or ROM). Write Word and Write Configuration Word commands For Write commands, a total of 32 significant bits have to be transferred from reader to EM4069. The 32 bits are transferred in a sequence of 4 bytes. Each byte is headed with start bit at logic 0 (as in normal 8-bit command) and trailed with stop bit at logic 1. The antenna sends an uninterrupted sequence of 40 bits (32 command bits, 4 start bits and 4 stop bits). This data organization ensures re-synchronization of the EM4069 with the reader signal, and avoids that wrong data would be extracted due to missing or spurious clocks from the clock-extractor of the IC. The IC treats the Write command as follows: First byte received is treated in the same way as for an 8- bit command. In the case that the processing of the first byte detects a Write Word command, it first puts the modulator load OFF for 1/2 bit period. During this time, the antenna field is High (as stop bit is at logic one) so the internal power supply capacitor can be charged. Next the EM4069 transitions to Start Bit Detection State with modulator load ON and waits for start bit at logic 0. The time out value is 2 tRDB. If time out is reached before a start bit is detected, the IC then returns to the read mode. Normally the start bit comes already after 1 tRDB and the EM4069 then continues to process the next byte. After the fourth byte has been detected, the EM4069 verifies if the CRC check is OK and if the word, which is addressed for writing, is not protected by the configuration word. Next, power check is performed to determine whether there is enough power available to write EEPROM. This operation lasts 1.5-bit periods. In the case all conditions above are fulfilled (CRC, protection, power check) EEPROM is written. If one of the conditions fails, the EM4069 returns in read mode without writing EEPROM. |
Similar Part No. - EM4169A5WT11 |
|
Similar Description - EM4169A5WT11 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |