MOTOROLA
Chapter 29. Debug Support
29-21
Background Debug Mode (BDM)
29.5.3.1 ColdFire BDM Command Format
All ColdFire Family BDM commands include a 16-bit operation word followed by an
optional set of one or more extension words, as shown in Figure 29-15.
Table 29-18 describes BDM fields.
29.5.3.1.1 Extension Words as Required
Some commands require extension words for addresses and/or immediate data. Addresses
require two extension words because only absolute long addressing is permitted. Longword
accesses are forcibly longword-aligned and word accesses are forcibly word-aligned.
Immediate data can be 1 or 2 words long. Byte and word data each requires a single
extension word and longword data requires two extension words.
Operands and addresses are transferred most-significant word first. In the following
descriptions of the BDM command set, the optional set of extension words is defined as
address, data, or operand data.
15
10
9
8
7
6
5
4
3
2
0
Operation
0
R/W
Op Size
0
0
A/D
Register
Extension Word(s)
Figure 29-15. BDM Command Format
Table 29-18. BDM Field Descriptions
Bit
Name
Description
15–10
Operation Specifies the command. These values are listed in Table 29-17.
9
0
Reserved, should be cleared.
8
R/W
Direction of operand transfer.
0 Data is written to the CPU or to memory from the development system.
1 The transfer is from the CPU to the development system.
7–6
Op Size
Operand data size for sized operations. Addresses are expressed as 32-bit absolute values. Note that a
command performing a byte-sized memory read leaves the upper 8 bits of the response data undefined.
Referenced data is returned in the lower 8 bits of the response.
Operand Size
Bit Values
00 Byte
8 bits
01 Word
16 bits
10 Longword
32 bits
11 Reserved
—
5–4
00
Reserved, should be cleared.
3
A/D
Address/data. Determines whether the register field specifies a data or address register.
0 Indicates a data register.
1 Indicates an address register.
2–0
Register Contains
the register number in commands that operate on processor registers.
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 ...