Datasheet

ARMulator Basics

2.8 Memory modelling with mapfiles

This section contains the following subsections:

• Overview of memory modelling with mapfiles

• Clock frequency

• Selecting the mapfile memory model on page 2-28

• How the mapfile memory model calculates wait states on page 2-28

• Configuring the map memory model on page 2-29.

2.8.1 Overview of memory modelling with mapfiles

mapfile

is a memory model which you can configure yourself. You can specify the size,

access width, access type and access speeds of individual memory blocks in the memory

system in a memory map file (see Map files on page 4-59).

ARMulator simulates each memory access as it occurs. It counts wait states according

to the type of memory access.

The debugger internal variables

$memstats

and

$statistics

give details of accesses of

each cycle type, regions of memory accessed and time spent accessing each region (see

AXD and armsd Debuggers Guide for information on retrieving details of debugger

internal variables).

2.8.2 Clock frequency

You can configure the clock frequency used by

mapfile

from the debugger. See AXD and

armsd Debuggers Guide for details.

The clock frequency is used to determine the number of wait states to be added to each

memory access, as well as to calculate time from number of cycles.

If you do not specify a clock speed, a value of 20MHz is used. If you specify a number

without units, the units are Hz. You can specify Hz, kHz, or MHz.