Motorola MVME166IG/D2 manual Diagnostic Facilities, Gcsr Method

Diagnostic Facilities

GCSR Method

A remote processor can initiate program execution in the local MVME166 dual-port RAM by issuing a remote GO command using the VMEchip2 Global Control and Status Registers (GCSR). The remote processor places the MVME166 execution address in general purpose registers 0 and 1 (GPCSR0 and GPCSR1). The remote processor then sets bit 8 (SIG0) of the VMEchip2 LM/SIG register. This causes the MVME166 to install breakpoints and begin execution. The result is identical to the MPCR method (with status code B) described in the previous section.

The GCSR registers are accessed in the VMEbus short I/O space. Each general purpose register is two bytes wide, occurring at an even address. The general purpose register number 0 is at an offset of $8 (local bus) or $4 (VMEbus) from the start of the GCSR registers. The local bus base address for the GCSR is $FFF40100. The VMEbus base address for the GCSR depends on the group select value and the board select value programmed in the Local Control and Status Registers (LCSR) of the MVME166. The execution address is formed by reading the GCSR general purpose registers in the following manner:

GPCSR0	used as the upper 16 bits of the address
GPCSR1	used as the lower 16 bits of the address

3

The address appears as:

GPCSR0 GPCSR1

Diagnostic Facilities

The 166Bug package includes a complete set of hardware diagnostics intended for testing and troubleshooting of the MVME166. These diagnostics are completely described in the MVME167Bug Debugging Package User’s Manual. To use the diagnostics, switch directories to the diagnostic directory. If you are in the debugger directory, you can switch to the diagnostic directory by entering the debugger command Switch Directories (SD). The diagnostic prompt ("166-Diag>") appears. Refer to the MVME167Bug Debugging Package User’s Manual for complete descriptions of the diagnostic routines available and instructions on how to invoke them. Note that some diagnostics depend on restart defaults that are set up only in a particular restart mode. The documentation for such diagnostics includes restart information.

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