Chapter 3. Hardware Description and Reconfiguration
3-3
The Processor and Support Logic
located. If the source of interrupt is not capable of providing a vector, its interrupt should
be set up as autovector interrupt which directs the processor to a predefined entry into the
exception table (refer to the MCF5407 User's Manual).
The processor goes to an exception routine via the exception table. This table is in the Flash
and the VBR points to it. However, a copy of this table is made in the RAM starting at
$00000000. To set an exception vector, the user places the address of the exception handler
in the appropriate vector in the vector table located at $00000000, and then points the VBR
to $00000000.
The MCF5407 has four external interrupt request lines. You can program the external
interrupt request pins to level 1, 3, 5, and 7 or levels 2, 4, 6, and 7. The M5407C3 configures
these lines as level 1, 3, 5, and 7. There are also six internal interrupt requests from Timer0,
Timer1, Software watchdog timer, UART0, UART1, and MBUS. Each interrupt source,
external and internal, can be programmed for any priority level. In case of similar priority
level, a second relative priority between 0 to 3 will be assigned.
However, the software watchdog is programmed for Level 7, priority 2 and uninitialized
vector. The UART0 is programmed for Level 3, priority 2 and autovector. The UART1 is
programmed for Level 3, priority 1 and autovector. The M-Bus is at Level 3, priority 0 and
autovector. The Timers are at Level 5 with Timer0 with priority 3 and Timer1 with priority
2 and both for autovector.
NOTE:
No interrupt sources should have the same level and priority as
another. Programming two interrupt sources with the same
level and priority can result in undefined operation.
The M5407C3 uses -IRQ7 to support the ABORT function using the ABORT switch S2.
This switch is used to force a non-maskable interrupt (level 7, priority 3) if the user's
program execution should be aborted without issuing a RESET (refer to Chapter 2 for more
information on ABORT). Since the ABORT switch is not capable of generating a vector in
response to level seven interrupt acknowledge from the processor, the debugger programs
this request for autovector mode.
The -IRQ1 line of the MCF5407 is connected to the PCI connector J3 pin A6 signal INTA#.
The -IRQ5 line of the MCF5407 is connected to the PCI controller (U17) pin 12 signal
-IRQ_OUT.
Refer to MCF5407 User’s Manual for more information about the interrupt controller.
3.1.7 Internal SRAM
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