Motorola Espresso Maker MC68340 ユーザーズマニュアル

MOTOROLA

5- 85

Command Sequence:

 

LS ADDR

"NOT READY"

STACK

RETURN PC

MS ADDR

"NOT READY"

XXX

"ILLEGAL"

NEXT CMD

"NOT READY"

CALL

???

NORMAL 

MODE

XXX

BERR/AERR

NEXT CMD

"NOT READY"

FREEZE

NEGATED

PREFETCH

STARTED

Operand Data:

The 32-bit operand data is the starting location of the patch routine, which is the initial
PC upon exiting BDM.

Result Data:

None

As an example, consider the following code segment. It outputs a character from the
MC68340 serial module channel A.

CHKSTAT:

MOVE.B

SRA,D0

Move serial status to D0

BNE.B CHKSTAT

Loop until condition true

MOVE.B

TBA,OUTPUT

Transmit character

MISSING:

ANDI.B

#3,D0

Check for TxEMP flag

RTS

BDM and the CALL command can be used to patch the code as follows:

1. Breakpoint user program at CHKSTAT

2. Enter BDM

3. Execute CALL command to MISSING

4. Exit BDM

5. Execute MISSING code

6. Return to user program

5.6.2.8.14 Reset Peripherals (RST). RST asserts 

RESET

 for 512 clock cycles. The CPU

is not reset by this command. This command is synonymous with the CPU RESET
instruction.

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Freescale Semiconductor, Inc.

For More Information On This Product,

   Go to: www.freescale.com

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