STPMC1 datasheet(66/77 Pages) STMICROELECTRONICS

66 / 77 page

Theory of operation

STPMC1

66/77

Doc ID 15728 Rev 6

collect all addresses of CFG bits to be permanently set into some list

clear all OTP shadow latches

set the system signal RD

connect a current source of at least +14 V, 1 mA to 3 mA to VOTP

wait for VOTP voltage is stable

set one OTP shadow latch from the list

set the system signal WE

wait for 300 µs

clear the system signal WE

10. clear the OTP shadow latch which was set in step 6

11. until all wanted CFG bits are permanently set, repeat steps 5 to 11

12. disconnect the current source

13. wait for VOTP voltage is less than 3V

14. clear the system signal RD

15. read all data records, in the last two of them there is read back of CFG bits

16. if verification of CFG bits fails and there is still chance to pass, repeat steps 1 to 16

For set or clear steps, apply the timing shown in timing for data records reading with proper

signal on the SDATD. For step 15, apply the timing shown in timing for writing configuration

and mode bits.

For permanent set of the TSTD bit, which causes no more writing to the configuration bits,

the procedure above must be conducted in such way that steps 6 to 13 are performed in

series during single period of active SCS because the idle state of SCS would make the

signal TSTD immediately effective which in turn, would abort the procedure and possibly

destroy the device due to clearing of system signal RD and so, connecting all gates of 3 V

NMOS sense amplifiers of already permanently set CFG bits to the VOTP source.

STPMC1 Scheda tecnica(PDF) 66 Page - STMicroelectronics