Motorola MC68VZ328 16.2.3 In-Circuit Emulation Module Control Register

16-8 MC68VZ328 User’s Manual 

Programming Model

16.2.3 In-Circuit Emulation Module Control Register

The in-circuit emulation module control regist er (ICEMCR) is used to control the in-circuit emulation

module. The bit assignments for the ICE module control register are shown in the following register

display. The settings for the bits are described in Table16-4.

ICEMCR ICE Module Control Register 0x(FF)FFFFFD0C

BIT 151413121110987654 3 21BIT 0

SWEN BBIEN HMDIS SB PBEN CE N

TYPE rw rw rw rw rw rw

RESET 0 00000000000 0 0 0 0

0x0000

Table 16-4. ICE Module Control Register Description

Name Description Setting

Reserved

Bits 15–7 Reserved These bits are reserved and should

be set to 0.

SWEN

Bit 6 Software Enable EMU Module—In normal mode, writing to

this bit enables the breakpoint functio n. 0 = Disable breakpoint function.

1 = Enable breakpoint function.

Reserved

Bit 5 Reserved This bit is reserved and should be

set to 0.

BBIEN

Bit 4 Bus Break Interrupt Enable—When set, this bit enables the

generation of a level 7 interrupt on a bus breakpoint. 0 = Disable level 7 interrupt

generation on a bus breakpoint.

1 = Enable level 7 interrupt

generation on a bus breakpoint.

HMDIS

Bit 3 Hard-Map Disable—In emulation mode, this bit activates the

internal hard-map operation. When th is bit is clear, some

memory locations are hard-coded to the specific values

shown in Table16-5 on page 16-9. If this bit is set or in nor-

mal mode, memory reads to these locations refer to the exter-

nal memory.

Note: It is important to note that when writing to these

locations, all writes are occurring to extern al memory. When

the HMDIS bit is disabled, reads to these addresses are in

word or long-word sizes.

See Table16-5 on page 16-9.

Bit 2 Single BreakPoint—This bit controls the direction of the

EMUBRK signal. In multiple breakpoint mode, the external

address comparator will compare the lower address bits and

the internal comparator will compare the higher address bits

to generate a breakpoint matched signal.

0 = Configure the EMUBRK signal as

an input (multiple breakpoint

mode with external address

compare for the lower

addresses).

1 = Configure the EMUBRK signal as

an output (single breakpoint

based on the internal address

compare register).

PBEN

Bit 1 Program Break Enable—This bit is used to select a p rogram

or bus break. 0 = Select a b us break.

1 = Select a program break.