User`s manual

Multiprocessor Support (Remote Start)

1-32

Code P is used only by the MVME260x, MVME360x, MVME460x, and

MVME230x boards. You can only program FLASH memory by the MPCR

method. See the .PFLASH system call for a description of the FLASH

memory program control packet structure.

The status codes that may be set by the bus master are:

The Multiprocessor Address Register (MPAR) contains the second

of two words used to control communication between processors.

The MPAR contents specify the address at which execution for the

remote processor is to begin if the MPCR contains a

G or B. The

location of MPAR is calculated as MPCR plus 4. The MPAR is

organized as follows:

At power-up, the PPCBug self-test routines initialize RAM,

including the memory locations used for multi-processor support

(MPCR and MPAR).

The MPCR contains $00 at power-up, indicating that initialization

is not yet complete. As the initialization proceeds, the execution

path comes to the routine that displays the prompt. Before sending

the prompt, this routine places an

R in the MPCR to indicate that

initialization is complete. Then the prompt is sent.

P ($50) Program FLASH Memory. The MPAR is set to the

address of the FLASH memory program control packet.

R ($52) Ready; the Þrmware monitor is watching for a change

G ($47) Initiate code at the MPAR address in a manner similar

to the GD command.

B ($42) Initiate code at the MPAR address, with breakpoints

enabled, in a manner similar to the GO command.

Q ($51) Query: Request for residual data, build it, and return its

address in the MPAR.

S ($53) Start: Build residual data, then start code execution. The

execution address is expected in the MPAR, (as with the

GO command). Residual data is built and its address is

loaded into r3 before execution begins.

****(MPAR)