MOTOROLA
Chapter 8. System Control Module (SCM)
8-13
Internal Bus Arbitration
The initial state of the master priorities is M3 > M2 > M1 > M0. System software should
guarantee that the programmed M
n
_PRTY fields are unique, otherwise the hardware
defaults to the initial-state priorities.
Table 8-7. MPARK Field Description
Bits
Name
Description
31–26
—
Reserved, should be cleared.
25
M2_P_EN
DMA bandwith control enable
0 disable the use of the DMA's bandwidth control to elevate the priority of its bus requests.
1 enable the use of the DMA's bandwidth control to elevate the priority of its bus requests.
24
BCR24BIT
Enables the use of 24 bit byte count registers in the DMA module
0 DMA BCRs function as 16 bit counters.
1 DMA BCRs function as 24 bit counters.
23–22
M3_PRTY
Master priority level for master 3 (Fast Ethernet Controller)
00 fourth (lowest) priority
01 third priority
10 second priority
11 first (highest) priority
21–20
M2_PRTY
Master priority level for master 2 (DMA Controller)
00 fourth (lowest) priority
01 third priority
10 second priority
11 first (highest) priority
19–18
M0_PRTY
Master priority level for master 0 (ColdFire Core)
00 fourth (lowest) priority
01 third priority
10 second priority
11 first (highest) priority
17–16
M1_PRTY
Master priority level for master 1 (Not used in user mode)
00 fourth (lowest) priority
01 third priority
10 second priority
11 first (highest) priority
15
—
Reserved, should be cleared.
14
FIXED
Fixed or round robin arbitration
0 round robin arbitration
1 fixed arbitration
13
TIMEOUT
Timeout Enable
0 disable count for when a master is locked out by other masters.
1 enable count for when a master is locked out by other masters and allow access when
LCKOUT_TIME is reached.
12
PRKLAST
Park on the last active master or highest priority master if no masters are active
0 park on last active master
1 park on highest priority master
11–8
LCKOUT_TIME Lock-out Time. Lock-out time for a master being denied the bus.
The lock out time is defined as 2^ LCKOUT_TIME[3:0].
7–0
—
Reserved, should be cleared.
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 ...