mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 639

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

Table 30-18
30.5.3.1.1
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.
30.5.3.2 Command Sequence Diagrams
The command sequence diagram in
represents a 17-bit bus transfer. The top half of each bubble indicates the data the development system
sends to the debug module; the bottom half indicates the debug module’s response to the previous
development system commands. Command and result transactions overlap to minimize latency.
Freescale Semiconductor
15–10 Operation Specifies the command. These values are listed in
7–6
5–4
2–0
15
Bit
9
8
3
Register
Op Size
describes BDM fields.
Name
Extension Words as Required
R/W
A/D
00
0
Operation
Reserved, should be cleared.
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.
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.
00 Byte
01 Word
10 Longword
11 Reserved
Reserved, should be cleared.
Address/data. Determines whether the register field specifies a data or address register.
0 Indicates a data register.
1 Indicates an address register.
Contains the register number in commands that operate on processor registers.
Operand Size
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
Figure 30-15. BDM Command Format
Table 30-18. BDM Field Descriptions
10
Figure 30-16
Bit Values
8 bits
16 bits
32 bits
—
0
9
Extension Word(s)
R/W
8
shows serial bus traffic for commands. Each bubble
7
Op Size
Description
6
Table
0
5
30-17.
0
4
A/D
3
2
Register
Debug Support
0
30-21