Nxp Semiconductors UM10237 用户手册
UM10237_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 19 December 2008
510 of 792
NXP Semiconductors
UM10237
Chapter 18: LPC24XX CAN controllers CAN1/2
Fig 82. Semaphore procedure for reading an auto-stored message
read 1st word
SEM == 01?
SEM == 11?
clear SEM, write back 1st word
read 2nd and 3rd words
read 1st word
SEM == 00?
START
most recently read 1st, 2nd, and
3rd words are from the same
message
this message has not been
received since last check