Table of Contents
Advertisement
Mask Option
Control
M68EM05P18UM/D
MOTOROLA
In single-chip mode operation:
For an MC68HC805P18 MCU, the mask options will be determined
by which options have been programmed in the MOR EEPROM
locations ($3F00–$3F01). These registers must be programmed
using a dedicated programmer.
In emulation:
The first byte of mask options (MOR1–$3F00) is controlled initially by
what has been programmed in the MOR1 EEPROM location
(MOR1–$3F00). Alternatively, the mask options can be controlled via
software and allow mask option changes during a debug session.
Option changes can be accomplished by command entry (for
instance, the MM command) or by execution of user code (for
instance, STA instruction).
The procedure for changing MOR1 options during an emulation
session requires manipulation of the reserved register at location
$0011 and the MOR1 location. First, set bit 6 of register $0011 (write
a $40 to location $0011). If you use the memory modify (MM)
command, a "Write did not verify" message should be ignored. The
mask options can then be set by writing the desired mask option
register byte value to the MOR1 location ($3F00). To continue using
the modified mask options, leave register $0011 bit 6 set to 1.
The selected mask options will return to the default options
programmed in the MOR EEPROM location MOR1 if the MCU takes
any reset or bit 6 of register $0011 is cleared (write a $00 to $0011).
The second byte of mask options (MOR2–$3F01) is always controlled
through the eight positions of DIP switch SW1. The top position
controls the port A0 pin pullup/interrupt option and the bottom position
controls the port A7 pin pullup/interrupt option. Each option will be
enabled if its respective position is ON.
HC05EVS Configuration and Operation
HC05EVS Configuration and Operation
MC68HC(8)05P18 Emulation
39
Advertisement
Table of Contents
