UM10360 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
User manual Rev. 3 — 19 December 2013 382 of 841
NXP Semiconductors
UM10360
Chapter 16: LPC176x/5x CAN1/2
16.15 Configuration and search algorithm
The CAN Identifier Look-up Table Memory can contain explicit identifiers and groups of
CAN identifiers for Standard and Extended CAN Frame Formats. They are organized as a
sorted list or table with an increasing order of the Source CAN Channel (SCC) together
with CAN Identifier in each section.
SCC value equals CAN_controller - 1, i.e., SCC = 0 matches CAN1 and SCC = 1
matches CAN2.
Every CAN identifier is linked to an ID Index number. In case of a CAN Identifier match,
the matching ID Index is stored in the Identifier Index of the Frame Status Register
(CANRFS) of the according CAN Controller.
16.15.1 Acceptance filter search algorithm
The identifier screening process of the acceptance filter starts in the following order:
1. FullCAN (Standard Frame Format) Identifier Section
2. Explicit Standard Frame Format Identifier Section
3. Group of Standard Frame Format Identifier Section
4. Explicit Extended Frame Format Identifier Section
5. Group of Extended Frame Format Identifier Section
Note: Only activated sections will take part in the screening process.
In cases where equal message identifiers of same frame format are defined in more than
one section, the first match will end the screening process for this identifier.
For example, if the same Source CAN Channel in conjunction with the identifier is defined
in the FullCAN, the Explicit Standard Frame Format and the Group of Standard Frame
Format Identifier Sections, the screening will already be finished with the match in the
FullCAN section.
In the example of Figure 61
, Identifiers with their Source CAN Channel have been defined
in the FullCAN, Explicit and Group of Standard Frame Format Identifier Sections.
Table 352. FullCAN Interrupt and Capture register 1 (FCANIC1 - address 0x4003 C028) bit description
Bit Symbol Description Reset Value
0 IntPnd32 FullCan Interrupt Pending bit 32. 0
... IntPndx (32<x<63) FullCan Interrupt Pending bit x. 0
31 IntPnd63 FullCan Interrupt Pending bit 63. 0
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