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MOTOROLA
Chapter 29. Debug Support
29-33
Background Debug Mode (BDM)
Command Sequence:
Figure 29-34.
RCREG
Command Sequence
Operand Data:
The only operand is the 32-bit Rc control register select field.
Result Data:
Control register contents are returned as a longword,
most-significant word first. The implemented portion of registers
smaller than 32 bits is guaranteed correct; other bits are undefined.
BDM Accesses of the Stack Pointer Registers (A7: SSP, USP)
The V2 core of the MCF5282 supports two unique stack pointer (A7) registers: the
supervisor stack pointer (SSP) and the user stack pointer (USP). The hardware
implementation of these two programmable-visible 32-bit registers does not uniquely
identify one as the SSP and the other as the USP. Rather, the hardware uses one 32-bit
register as the currently-active A7 and the other register is named simply the “other_A7”.
Thus, the contents of the two hardware registers is a function of the operating mode of the
processor:
if SR[S] = 1
then
A7 = Supervisor Stack Pointer
other_A7 = User Stack Pointer
else
A7 = User Stack Pointer
other_A7 = Supervisor Stack Pointer
The BDM programming model supports reads and writes to the A7 and other_A7 registers
directly. It is the responsibility of the external development system to determine the
mapping of the two hardware registers (A7, other_A7) to the two program-visible
definitions (supervisor and user stack pointers), based on the Supervisor bit of the status
register.
BDM Accesses of the EMAC Registers
The presence of rounding logic in the output datapath of the EMAC requires that special
care be taken during any BDM-initiated reads and writes of its programming model. In
particular, it is necessary that any result rounding modes be disabled during the read/write
process so the exact bit-wise contents of the EMAC registers are accessed.
XXX
’NOT READY’
RCREG
???
MS ADDR
’NOT READY’
MS ADDR
’NOT READY’
NEXT CMD
’NOT READY’
READ
CONTROL
REGISTER
XXX
BERR
NEXT CMD
MS RESULT
NEXT CMD
LS RESULT
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 ...