RESET [addr]      - MCU Hardware Reset with Existing/New Reset Vector.

This command causes the MCU to generate a hardware reset and optionally start 
execution of user code at  or at the address specified by a previous RESET 
command. Once the reset occurs, the default implementation of PCbug11 causes the 
talker code to re-initialised, and then the MCU either idles, if no user 
specified address was given in the command line, or the talker code jumps to the 
address specified by  on the command line.

Note that once  has been specified, it is maintained in the talker code until
replaced by another value. Refer to the appropriate talker code source listing for details.

Note:
To simulate an external hardware reset, the RESET command forces the MCU to 
generate an internal reset which also causes the external RESET pin to go low.
To produce the internal reset, the Clock Monitor Fail detector is used. 

PCbug11 implements this by downloading and executing the following code in a 
reserved area of RAM:

	STY cme_jmp    Clock monitor fail jump address
	STAA OPTION,X  OPTION=$39
	STAB TEST1,X   TEST1=$3E
	STOP
	JMP user_start <- in case STOP doesn't generate CME reset!
Where:
	Y=user reset address

X=$1000   Default I/O register base address for M68HC11 
ACCA=$08  Enables the clock monitor in the OPTION reg.

The values passed to ACCB, CCR and Y depend on the MCU type & operating mode.

In Bootstrap mode: If MCU is an 'A8, ACCB=0 to clear the DISR bit in TEST1 reg. 
             For all other devices, ACCB=4 to force the clock monitor reset by 
             setting the FCM bit in TEST1 reg. For all devices, CCR=$40 to enable 
             the STOP instruction and I bit interrupts, and disable XIRQ to allow 
             execution of the instruction after STOP if all else fails! 
             The user reset address is $0000.
In External mode:  For all devices, ACCB=$0, since TEST1 is not accessible in 
             normal modes. CCR=$10 to enable STOP and XIRQ, and disable I bit 
             interrupts. The user reset address is defined by the user in the 
             appropriate .MAP file.

Note also that the above reset code forces the value in the Clock Monitor Fail 
vector, before starting user code execution. This means that the user must 
dynamically assign this vector in software before using the feature. The effect 
of this internal reset is identical to an external hardware reset, except that 
the COP Clock Monitor fail vector is taken instead of the RESET vector - provided 
the rising edge of the reset output signal is not delayed by external capacitance. 

Refer to the M68HC11 data book and User manual for details.


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