![Freescale Semiconductor MCF54455 Скачать руководство пользователя страница 873](http://html1.mh-extra.com/html/freescale-semiconductor/mcf54455/mcf54455_reference-manual_2330541873.webp)
Debug Module
34-31
Freescale Semiconductor
34.4.1.3.3
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, while 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.
34.4.1.4
Command Sequence Diagrams
The command sequence diagram in
shows serial bus traffic for commands. Each bubble
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.
Figure 34-20. Command Sequence Diagram
3
A/D
Address/Data. Determines whether the register field specifies a data or address register.
0 Data register.
1 Address register.
2–0
Register
Contains the register number in commands that operate on processor registers. See
Table 34-24. BDM Field Descriptions (continued)
Field
Description
XXX
’NOT READY’
READ (LONG)
???
MS ADDR
’NOT READY’
LS ADDR
’NOT READY’
NEXT CMD
’NOT READY’
NEXT CMD
’NOT READY’
NEXT CMD
LS RESULT
Commands transmitted to the debug module
Command code transmitted during this cycle
High-order 16 bits of memory address
Low-order 16 bits of memory address
Non-serial-related
Next
Command
Code
Sequence taken if operation
has not completed
activity
READ
MEMORY
LOCATION
XXX
BERR
XXX
MS RESULT
XXX
’ILLEGAL’
Responses from the debug module
Results from previous command
Sequence taken if illegal command
is received by debug module
Data used from this transfer
Sequence taken if bus error
occurs on memory access
High- and low-order 16 bits of result
Содержание MCF54455
Страница 33: ...xxviii Freescale Semiconductor ...
Страница 67: ...Freescale Semiconductor 1 ...
Страница 125: ...Freescale Semiconductor 1 ...
Страница 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Страница 173: ...Cache 6 28 Freescale Semiconductor ...
Страница 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Страница 207: ...Power Management 9 16 Freescale Semiconductor ...
Страница 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Страница 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Страница 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Страница 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Страница 601: ...Freescale Semiconductor 1 ...
Страница 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Страница 843: ...Freescale Semiconductor 1 ...
Страница 921: ...Revision History A 6 Freescale Semiconductor ...