General System Overview
Power-Up Sequence
During the power-up routine, initialisation of hardware is performed as described in this
Manual.
The 68000 CPU fetches the initial Supervisor Stack Pointer and start address from
locations $0 and $4. These are the first 8 bytes of the system EPROM area; they are
down mapped to provide a defined start following a reset or during power-up. They pass
control to the Monitor firmware which performs all the necessary initialisation routines.
$0000
Initial Supervisor Stack
$0003
$0004
Initial Start Address
$0007
RESET Switch
RESET is provided by Switch 1 (SW1) on the PME 68-1B front panel. Pressing this
switch causes all programs or processes to terminate, resets the CPU and the parallel
I/O devices, and restarts the resident firmware. The RESET switch may be used if ‘all
else fails’.
ABORT Switch
The ABORT switch is SW2 on the CPU front panel. It causes an interrupt at the highest
priority level (IRQ level 7 of the CPU); it cannot be masked or disabled. Control is
immediately transferred via the interrupt service routine to the Monitor main control
routine. ABORT also causes the contents of the 68000 internal registers to be displayed.
ABORT differs from RESET in that the processor register and memory contents are
not modified and the status of the processor registers and peripherals is not changed.
Using the abort function or trace breakpoints is the best way to debug software as the
user can interrupt the processor without destroying the present state of the system.
PME68-1B Manual
Page 77 Issue 5
Содержание PME 68-1B
Страница 8: ...Figure 1 The PME 68 1B Board Photograph not available in PDF PME 68 1B Manual Page 2 Issue 5...
Страница 12: ...Figure 4 Component Layout Diagram P5 P4 P3 BAT PME 68 1B Manual Page 6 Issue 5...
Страница 56: ...Figure 14 Link Areas BAT PME68 1B Manual Page 50 Issue 5...
Страница 57: ...Blank Page PME68 1B Manual Page 51 Issue 5...
Страница 59: ...Figure 15 Location of System EPROM Area 1 2 3 4 1 2 3 4 WC1 WC2 PME68 1B Manual Page 53 Issue 5...
Страница 80: ...Figure 41 Location of BERR Jumpers 1 2 3 4 WK1 WK2 BR26 2 3 1 BAT PME68 1B Manual Page 74 Issue 5...
Страница 132: ...Blank Page PME68 1B Manual Page 126 Issue 5...