
ADuC845/ADuC847/ADuC848
Rev. B | Page 50 of 108
de.
w
ry can also be
t
.
an
e
Figure 30. ULOAD mode can be used to upgrade the code in
load protocol. By configuring
ve, it
,
ode can be used to save data to the
n be extremely useful in
f the 62 kbytes of Flash/EE program
means
re, it
rased or reprogrammed by erroneous
r
ing the Flash/EE program memory via ULOAD
th
ry Control SFR
d
Note uC007
USER DOWNLOAD MODE (ULOAD)
Flash/EE program memory available to the user as one single
block of memory. In this mode, all the Flash/EE memory is
read-only to user co
Ho ever, most of the Flash/EE program memo
wri ten to during run time simply by entering ULOAD mode
In ULOAD mode, the lower 56 kbytes of program memory c
be rased and reprogrammed by the user software as shown in
the field via any user-defined down
the SPI port on the ADuC845/ADuC847/ADuC848 as a sla
is possible to completely reprogram the 56 kbytes of Flash/EE
program memory in under 5 s (see Application Note uC007
Alternatively, ULOAD m
56 kbytes of Flash/EE memory. This ca
data logging applications where the parts can provide up to
60 kbytes of data memory on-chip (4 kbytes of dedicated
Flash/EE data memory also exist).
The upper 6 kbytes o
memory (8 kbytes on the 32-kbyte parts) are programmable
only via serial download or parallel programming. This
ead-only to user code; therefo
that this space appears as r
cannot be accidentally e
code execution, making it very suitable to use the 6 kbytes as a
bootloader. A bootload enable option exists in the Windows
serial downloader (WSD) to “Always RUN from E000H after
Reset.” If using a bootloader, this option is recommended to
ensure that the bootloader always executes correct code afte
reset.
Programm
mode is described in
e Flash/EE Memo
section of ECON an also in Application
(www.analog.com/microconverter).
EMBEDDED DOWNLOAD/DEBUG KERNEL
PERMANENTLY EMBEDDED FIRMWARE ALLOWS
CODE TO BE DOWNLOADED TO ANY OF THE
62 kBYTES OF ON-CHIP PROGRAM MEMORY.
THE KERNEL PROGRAM APPEARS AS NOP
INSTRUCTIONS TO USER CODE.
USER BOOTLOADER SPACE
THE USER BOOTLOADER
SPACE CAN BE PROGRAMMED IN
DOWNLOAD/DEBUG MODE VIA THE
KERNEL BUT IS READ ONLY WHEN
EXECUTING USER CODE
USER DOWNLOADER SPACE
EITHER THE DOWNLOAD/DEBUG
KERNEL OR USER CODE (IN
CAN PROGRAM
ULOAD MODE)
THIS SPACE
FFFFH
2kBYTE
F8
F7FFH
6kBYTE
E000H
dFFFH
00H
56kBYTE
0000H
04741-031
Figure 30. Flash/EE Program Memory Map in ULOAD Mode (62-kbyte Part)
starting at 6000H. The memory mapping is shown in
Figure 31.62 kBYTES
OF USER
CODE
MEMORY
The 32-kbyte memory parts have the user bootload space
EMBEDDED DOWNLOAD/DEBUG KERNEL
PERMANENTLY EMBEDDED FIRMWARE ALLOWS
CODE TO BE DOWNLOADED TO ANY OF THE
32 kBYTES OF ON-CHIP PROGRAM MEMORY.
THE KERNEL PROGRAM APPEARS AS NOP
INSTRUCTIONS TO USER CODE.
USER BOOTLOADER SPACE
THE USER BOOTLOADER
SPACE CAN BE PROGRAMMED IN
DOWNLOAD/DEBUG MODE VIA THE
KERNEL BUT IS READ ONLY WHEN
EXECUTING USER CODE
USER DOWNLOADER SPACE
EITHER THE DOWNLOAD/DEBUG
KERNEL OR USER CODE (IN ULOAD
MODE) CAN PROGRAM THIS SPACE
NOT AVAILABLE TO USER
FFFFH
2kBYTE
F800H
8000H
8kBYTE
6000H
5FFFH
24kBYTE
0000H
04741-074
32 kBYTES
OF USER
CODE
MEMORY
Figure 31. Flash/EE Program Memory Map in ULOAD Mode (32-kbyte Part)
ULOAD mode is not available on the 8-kbyte Flash/EE program
memory parts.
Flash/EE Program Memory Security
The ADuC845/ADuC847/ADuC848 facilitate three modes of
Flash/EE program memory security: the lock, secure, and serial
safe modes. These modes can be independently activated,
restricting access to the internal code space. They can be
enabled as part of serial download protocol, as described in
Application Note uC004, or via parallel programming.
Lock Mode
This mode locks the code memory, disabling parallel program-
ming of the program memory. However, reading the memory in
parallel mode and reading the memory via a MOVC command
from external memory are still allowed. This mode is deactivated
by initiating an ERASE CODE AND DATA command in serial
download or parallel programming modes.
Secure Mode
This mode locks the code memory, disabling parallel program-
ming of the program memory. Reading/verifying the memory
in parallel mode and reading the internal memory via a MOVC
command from external memory are also disabled. This mode
is deactivated by initiating an ERASE CODE AND DATA
command in serial download or parallel programming modes.
Serial Safe Mode
This mode disables serial download capability on the device. If
serial safe mode is activated and an attempt is made to reset the
part into serial download mode, that is, RESET asserted (pulled
high) and de-asserted (pulled low) with PSEN low, the part
interprets the serial download reset as a normal reset only. It
therefore does not enter serial download mode, but executes only
a normal reset sequence. Serial safe mode can be disabled only
by initiating an ERASE CODE AND DATA command in
parallel programming mode.