Multiprocessor Support
B-23
B
The status codes stored in the MPCR are of two types:
❏
Status returned (from the monitor)
❏
Status set (by the bus master)
The status codes that may be returned from the monitor are:
The status codes that may be set by the bus master are:
The Multiprocessor Address Register (MPAR), located in shared
RAM location of $804 offset from the base address the debugger
loads it at, contains the second of two longwords 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 MPAR is organized as follows:
At power-up, the debug monitor self-test routines initialize RAM,
including the memory locations used for multi-processor support
($800 through $807).
The MPCR contains $00 at power-up, indicating that initialization
is not yet complete. As the initialization proceeds, the execution
path comes to the ÒpromptÓ routine. Before sending the prompt,
this routine places an R in the MPCR to indicate that initialization
is complete. Then the prompt is sent.
If no terminal is connected to the port, the MPCR is still polled to
determine whether an external processor requires control to be
passed to the dual-port RAM. If a terminal does respond, the MPCR
is polled for the same purpose while the serial port is being polled
for user input.
HEX
0
(HEX 00)
--
Wait. Initialization not yet complete.
ASCII R
(HEX 52)
--
Ready. The Þrmware monitor is watching for a change.
ASCII E
(HEX 45)
--
Code pointed to by the MPAR address is executing.
ASCII G
(HEX 47)
--
Use Go Direct (
GD
) logic specifying the MPAR address.
ASCII B
(HEX 42)
--
Install breakpoints using the Go (
G
) logic.
$804 *
*
*
*
(MPAR)
Summary of Contents for MVME177
Page 1: ...MVME177 Single Board Computer Installation and Use Manual VME177A IH2 ...
Page 6: ......
Page 42: ...Hardware Preparation and Installation 2 18 2 ...
Page 52: ...Operating Instructions 3 10 3 ...
Page 80: ...EIA 232 D Interconnections A 8 A ...