Zilog EZ80F916 - Manual (Page 98)

UM014423-0607 Using the Integrated Development Environment
ZiLOG Developer Studio II
eZ80Acclaim! ® User Manual
78
project on the target. As an example, the internal and external Flash memory on the
eZ80F91 development kit use different Flash algorithms so the Target memory
range must contain at least a 0x40 byte gap between these two Flash regions.
•
All RAM
This configuration produces a single memory image that resides in, and executes
from, RAM. This configuration is most useful when emulating code from RAM on the
eZ80L92 and eZ80190 evaluation boards. Using the ZDS II standard startup module
with this configuration is recommended as the surest and easiest way to produce an
effective run-time environment.
In this configuration, the linker maps all segments associated with the logical ROM
address space to physical RAM. ZDS II therefore automatically generates two linker
commands:
GROUP MEMORY=ROM,RAM
This command defines a new address space (MEMORY) that contains the existing
logical address spaces RAM and ROM.
RANGE MEMORY $0 : $FFFF
This command defines the physical address range for the combined spaces.
ZDS II creates the RANGE command starting with the lowest address specified in the
Address Spaces page and ending with the highest address. The lowest address is
min(min(ROM), min(RAM))
and the highest address is
max(max(ROM),max(RAM))
. These two ZDS II-generated commands are critical for
building an All RAM configuration.
Both the
GROUP MEMORY
and
RANGE MEMORY
commands are required for the All
RAM configuration. If the
RANGE MEMORY
command is omitted, the result can be
wasted space. To illustrate the effects of such an error, suppose the Address Spaces
page has the following values for a 64K memory machine:
ROM 0-7FFF
RAM 8000-FFFF
If the All RAM configuration is not used to create the linker command file, ZDS II
converts the values in the Address Spaces page to the following linker commands:
RANGE ROM $0 : $7FFF
RANGE RAM $8000 : $FFFF
which, if followed by
GROUP MEMORY=ROM,RAM
would result in ROM segments starting at address 0h and RAM segments starting at
8000h
, potentially wasting space if the ROM segments do not fully occupy the range
from
0h - 7FFFh
. The
RANGE MEMORY 0h : FFFFh
command overrides the