Mode differences – Freescale Semiconductor MC68HC08KH12 User Manual

Page 153

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MC68HC(7)08KH12

Rev. 1.1

Advance Information

Freescale Semiconductor

153

When the host computer has completed downloading code into the MCU
RAM, This code can be executed by driving PTA0 low while asserting
RST low and then high. The internal monitor ROM firmware will interpret
the low on PTA0 as an indication to jump to RAM, and execution control
will then continue from RAM. Execution of an SWI from the downloaded
code will return program control to the internal monitor ROM firmware.
Alternatively, the host can send a RUN command, which executes an
RTI, and this can be used to send control to the address on the stack
pointer.

The COP module is disabled in monitor mode as long as V

DD

+ V

HI

is

applied to either the IRQ1/V

PP

pin or the RST pin. (

See Section 7.

System Integration Module (SIM)

for more information on modes of

operation.)

Table 10-2

is a summary of the differences between user mode and

monitor mode.

Table 10-2. Mode Differences

Modes

Functions

COP

Reset

Vector

High

Reset

Vector

Low

Break

Vector

High

Break

Vector

Low

SWI

Vector

High

SWI

Vector

Low

User

Enabled

$FFFE

$FFFF

$FFFC

$FFFD

$FFFC

$FFFD

Monitor

Disabled

(1)

1. If the high voltage (V

DD

+ V

HI

) is removed from the IRQ1/V

PP

pin or the RST pin, the SIM

asserts its COP enable output. The COP is a mask option enabled or disabled by the
COPD bit in the configuration register.

$FEFE

$FEFF

$FEFC

$FEFD

$FEFC

$FEFD

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