Motorola CPCI-6115 - Manual (Page 118)

CPCI-6115 CompactPCI Single Board Computer Installation and Use (6806800A68D)
Remote Start via the PCI Bus Command/Response Register Description
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MOTLoad uses certain areas of memory and I/O devices for its own operation. This interface
allows the host CPU to write and read any location on the local CPU bus including those in use
by the firmware. Host CPUs should interrogate the firmware via the memory size query
command (as described in Opcode 0x05: Memory size Query in Appendix B of the MOTLoad
Firmware Packager User’s Manual) and avoid overwriting memory which is in-use by firmware;
otherwise, erratic behavior may result.
6.3 Command/Response Register Description
The Intel 2155x SCRATCH7 register is used as the command/response register. In this register
description, and the following command descriptions, references to the upper half of the register
refer to bits 0 through 15, and references to the lower half of the register refer to bits 16 through
31.
Format of command/response register (Intel 2155x SCRATCH7):
At reset, hardware clears this register. After reset, firmware writes this register with the value
0x80525354. This value indicates that a reset event has occurred and the interface is ready to
accept commands.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
O
W
N Command opcode E
R
R
Command Options Command Data/Result
Bit Number Description
Bit 0 The ownership flag (OWN). A value of 1 indicates the’host’ owns the
register. A value of 0 indicates that the local CPU owns the register.
Bits 1 to 7 7 bit command opcode field. Each command is described in more detail in
the MOTLoad Firmware Package User’s Manual.
Bit 8 Global error status flag (ERR). If the command completed successfully,
then this bit is written with the value 0 at command completion. If the
command fails, it will be written with the value 1. Additional command
specific error status may be returned in other fields of the register.
Bits 9 to 15 7 bit command option field. Each command specifies the particular
meaning of each of the command option bits. Option bits that are unused
are considered reserved and should be written to 0 to ensure compatibility
with future implementations of this interface.
For most commands, bit 9 is used to specify verbose/non-verbose mode
target command processing. In verbose mode, command related
information is printed on the target console as the host command is
processed. Verbose mode is selected when bit 9=0, non-verbose mode is
set when bit 9=1.
Bits 16 to 31 16 bit data/result field. The meaning of this field is specific to each
command opcode. Refer to the MOTLoad Firmware Package User’s
Manual for error codes.