PK-HC08QY4 Freescale Semiconductor, PK-HC08QY4 Datasheet - Page 28

• Manufacturer Part Number: PK-HC08QY4
• Description: KIT STARTER 908QY4
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of PK-HC08QY4

• Contents: Board
• For Use With/related Products: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4. The IRQ handling routine must include the following code:
Breakpoints and Swi Instruction
The HC08’s on-chip debug module only handles one hardware breakpoint. However, you
can force the program execution to stop at other specific locations by inserting the “swi”
Assembly instruction on your source code.
Interrupt Execution during Steps
When issuing stepping instructions and there are pending interrupts, the debugger will not
step inside the interrupt handling routine, but the whole interrupt handling routine is
executed. An exception is when you single step on an Assembly instruction which branches
to itself: in this case, interrupts which may occur are not handled.
Reading Peripheral Status
Care must be taken when reading some peripheral’s status/data registers, since a reading
operations may cause the clearing of flags. This may happen when the Memory window or
the Data window is open, since these windows read microcontroller’s resources during
refresh operations.
Internal RC Oscillator Calibration
The MC68HC908QY microcontroller features an internal, trimmerable RC oscillator working
at 3.2 MHz. The MC68HC908QY microcontroller is factory pre-programmed with a default
trimming value in a dedicated FLASH location (specified in the datasheet). However, due to
the different real-world conditions of the user’s system, it is always suggested to recalibrate
the internal oscillator to reflect the actual working conditions.
The Trimming Settings dialog box allows you to enable/disable the trimming feature. If
enabled, it is possible to specify whether to save the calculated trimmed value in the default
location (the location suggested either by Freescale or SofTec Microsystems, restorable at
bil *
swi
rti
; Waits for the IRQ signal to go high
; Jumps to monitor code
; Returns from interrupt
PK-HC08QY4 User's Manual
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