Motorola MVME187 User Manual

Multiprocessor Support

4-23

3. As the initialization proceeds, the execution path comes to the 

"prompt" routine. 

Before sending the prompt, this routine places an R in the 
MPCR to indicate that initialization is complete. Then the 
prompt is sent. 

РIf no terminal is connected to the port, the MPCR is still 

polled to see whether an external processor requires 
control to be passed to the dual-port RAM. 

РIf a terminal does respond, the MPCR is polled for the 

same purpose while the serial port is being polled for user 
input. 

РAn ASCII G placed in the MPCR by a remote processor 

indicates that the Go Direct type of transfer is requested. 

РAn ASCII B in the MPCR indicates that breakpoints are to 

be armed before control is transferred (as with the GO 
command). 

In either sequence, an E is placed in the MPCR to indicate 
that execution is underway just before control is passed to 
RAM. (Any remote processor could examine the MPCR 
contents.) 

4. If the code being executed in dual-port RAM is to reenter the 

debug monitor, a TRAP #496 call using function $0063 
(SYSCALL .RETURN) returns control to the monitor with a 
new display prompt. 

Note that every time the debug monitor returns to the 
prompt, an R is moved into the MPCR to indicate that control 
can be transferred once again to a specified RAM location.