Freescale Semiconductor MCF5480 - Manual (Page 291)

Background Debug Mode (BDM)
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 8-41
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.
8.5.3.3.6 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:
15 12 11 8 7 4 3 0
Byte 0x1 0xC 0x0 0x0
X X X X X X X X D[7:0]
Word 0x1 0xC 0x4 0x0
D[15:0]
Longword 0x1 0xC 0x8 0x0
D[31:16]
D[15:0]
Figure 8-33. FILL Command Format