6 fill memory block (fill) – Motorola ColdFire MCF5281 User Manual

Page 647

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Debug Support

Freescale Semiconductor

30-29

Command Sequence:

Figure 30-26.

DUMP

Command Sequence

Operand Data:

None

Result Data:

Requested data is returned as either a word or longword. Byte data is returned in
the least-significant byte of a word result. Word results return 16 bits of significant
data; longword results return 32 bits. A value of 0x0001 (with S set) is returned if
a bus error occurs.

30.5.3.3.6

Fill Memory Block (

FILL

)

A

FILL

command is used with the

WRITE

command to access large blocks of memory. An initial

WRITE

is

executed to set up the starting address of the block and to supply the first operand. The

FILL

command

writes subsequent operands. The initial address is incremented by the operand size (1, 2, or 4) and saved
in a temporary register after the memory write. Subsequent

FILL

commands use this address, perform the

write, increment it by the current operand size, and store the updated address in the temporary register.

If an initial

WRITE

is not executed preceding the first

FILL

command, the illegal command response is

returned.

NOTE

The

FILL

command does not check for a valid address—

FILL

is a valid

command only when preceded by another

FILL

, a

NOP

, or a

WRITE

command.

Otherwise, an illegal command response is returned. The

NOP

command can

be used for intercommand padding without corrupting the address pointer.

The size field is examined each time a

FILL

command is processed, allowing the operand size to be altered

dynamically.

Command Formats:

XXX

’NOT READY’

DUMP (B/W)

???

XXX

’ILLEGAL’

NEXT CMD

’NOT READY’

NEXT CMD

’NOT READY’

READ

MEMORY

LOCATION

XXX

BERR

NEXT CMD

RESULT

XXX

’NOT READY’

DUMP (LONG)

???

XXX

’ILLEGAL’

NEXT CMD

’NOT READY’

NEXT CMD

’NOT READY’

READ

MEMORY

LOCATION

XXX

BERR

NEXT CMD

MS RESULT

NEXT CMD

LS RESULT

MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3

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