25-26
MCF5282 User’s Manual
MOTOROLA
Programmer’s Model
25.5.6 Free Running Timer (TIMER)
Table 25-14 describes the TIMER fields.
25.5.7 Rx Mask Registers
These registers are used as acceptance masks for received frame IDs. 3 masks are defined:
A global mask, used for Rx buffers 0-13, and 2 more separate masks for buffers 14 and 15.
Mask bit = 0: The corresponding incoming ID bit is “don’t care”.
Mask bit = 1: The corresponding ID bit is checked against the incoming ID bit, to see if a
match exists.
Note that these masks are used both for Standard and Extended ID formats. The value of
mask registers should NOT be changed while in normal operation, as locked frames which
matched a MB through a mask, may be transferred into the MB (upon release) but may no
longer match.
15
0
Field
TIMER
Reset
0000_0000_0000_0000
R/W
R/W
Address
0x1C_000A
Figure 25-11. Free Running Timer (TIMER)
Table 25-14. TIMER Field Descriptions
Bits
Name
Description
15–0 TIMER The free running timer counter can be read and written by the CPU. The timer starts from zero after
reset, counts linearly to 0xFFFF, and wraps around.
The timer is clocked by the FlexCAN bit-clock. During a message, it increments by one for each bit that
is received or transmitted. When there is no message on the bus, it increments at the nominal bit rate.
The timer value is captured at the beginning of the identifier field of any frame on the CAN bus. The
captured value is written into the “time stamp” entry in a message buffer after a successful reception
or transmission of a message.
Table 25-15. Mask examples for Normal/Extended Messages
Base ID
ID28.................ID18
I
D
E
Extended ID
ID17......................................ID0
Match
MB2-Id
1 1 1 1 1 1 1 1 0 0 0
0
MB3-Id
1 1 1 1 1 1 1 1 0 0 0
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
MB4-Id
0 0 0 0 0 0 1 1 1 1 1
0
MB5-Id
0 0 0 0 0 0 1 1 1 0 1
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
Summary of Contents for ColdFire MCF5281
Page 124: ...3 20 MCF5282 User s Manual MOTOROLA EMAC Instruction Set Summary ...
Page 141: ...MOTOROLA Chapter 5 Static RAM SRAM 5 5 SRAM Programming Model ...
Page 142: ...5 6 MCF5282 User s Manual MOTOROLA SRAM Programming Model ...
Page 168: ...6 26 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 186: ...7 18 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 228: ...9 22 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 246: ...10 18 MCF5282 User s Manual MOTOROLA Low Power Wakeup Operation ...
Page 254: ...11 8 MCF5282 User s Manual MOTOROLA Memory Map and Registers ...
Page 264: ...12 10 MCF5282 User s Manual MOTOROLA Chip Select Registers ...
Page 280: ...13 16 MCF5282 User s Manual MOTOROLA Misaligned Operands ...
Page 314: ...14 34 MCF5282 User s Manual MOTOROLA MCF5282 External Signals ...
Page 339: ...MOTOROLA Chapter 15 Synchronous DRAM Controller Module 15 25 SDRAM Example ...
Page 340: ...15 26 MCF5282 User s Manual MOTOROLA SDRAM Example ...
Page 356: ...16 16 MCF5282 User s Manual MOTOROLA DMA Controller Module Functional Description ...
Page 408: ...17 52 MCF5282 User s Manual MOTOROLA Buffer Descriptors ...
Page 446: ...20 24 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 474: ...22 18 MCF5282 User s Manual MOTOROLA Programming Model ...
Page 510: ...23 36 MCF5282 User s Manual MOTOROLA Operation ...
Page 526: ...24 16 MCF5282 User s Manual MOTOROLA I2C Programming Examples ...
Page 672: ...28 12 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 718: ...29 46 MCF5282 User s Manual MOTOROLA Motorola Recommended BDM Pinout ...
Page 750: ...32 8 MCF5282 User s Manual MOTOROLA Ordering Information ...