Nxp Semiconductors UM10237 ユーザーズマニュアル
UM10237_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 19 December 2008
498 of 792
NXP Semiconductors
UM10237
Chapter 18: LPC24XX CAN controllers CAN1/2
12.2 Acceptance filter Bypass mode
The Acceptance Filter Bypass Mode can be used for example to change the acceptance
filter configuration during a running system, e.g. change of identifiers in the ID-Look-up
Table memory. During this re-configuration, software acceptance filtering has to be used.
filter configuration during a running system, e.g. change of identifiers in the ID-Look-up
Table memory. During this re-configuration, software acceptance filtering has to be used.
It is recommended to use the ID ready Interrupt (ID Index) and the Receive Interrupt (RI).
In this mode all CAN message are accepted and stored in the Receive Buffers of active
CAN Controllers.
In this mode all CAN message are accepted and stored in the Receive Buffers of active
CAN Controllers.
12.3 Acceptance filter Operating mode
The Acceptance Filter is in Operating Mode when neither the AccOff nor the AccBP in the
Configuration Register is set and the eFCAN = 0.
Configuration Register is set and the eFCAN = 0.
12.4 FullCAN mode
The Acceptance Filter is in Operating Mode when neither the AccOff nor the AccBP in the
Configuration Register is set and the eFCAN = 1. More details on FullCAN mode are
available in
Configuration Register is set and the eFCAN = 1. More details on FullCAN mode are
available in
13. Sections of the ID look-up table RAM
Four 12-bit section configuration registers (SFF_sa, SFF_GRP_sa, EFF_sa,
EFF_GRP_sa) are used to define the boundaries of the different identifier sections in the
ID-Look-up Table Memory. The fifth 12-bit section configuration register, the End of Table
address register (ENDofTable) is used to define the end of all identifier sections. The End
of Table address is also used to assign the start address of the section where FullCAN
Message Objects, if enabled are stored.
EFF_GRP_sa) are used to define the boundaries of the different identifier sections in the
ID-Look-up Table Memory. The fifth 12-bit section configuration register, the End of Table
address register (ENDofTable) is used to define the end of all identifier sections. The End
of Table address is also used to assign the start address of the section where FullCAN
Message Objects, if enabled are stored.
14. ID look-up table RAM
The Whole ID Look-up Table RAM is only word accessible. A write access is only possible
during the Acceptance Filter Off or Bypass Mode. Read access is allowed in all
Acceptance Filter Modes.
during the Acceptance Filter Off or Bypass Mode. Read access is allowed in all
Acceptance Filter Modes.
Table 442. Section configuration register settings
ID-Look up Table Section
Register
Value
Section
status
status
FullCAN (Standard Frame Format) Identifier Section
SFF_sa
= 0x000
disabled
> 0x000
enabled
Explicit Standard Frame Format Identifier Section
SFF_GRP_sa = SFF_sa
disabled
> SFF_sa
enabled
Group of Standard Frame Format Identifier Section
EFF_sa
= SFF_GRP_sa disabled
> SFF_GRP_sa enabled
Explicit Extended Frame Format Identifier Section
EFF_GRP_sa = EFF_sa
disabled
> EFF_sa
enabled
Group of Extended Frame Format Identifier Section
ENDofTable
= EFF_GRP_sa disabled
> EFF_GRP_sa enabled