ADUC847BCP8-5 AD [Analog Devices], ADUC847BCP8-5 Datasheet - Page 50

• Manufacturer Part Number: ADUC847BCP8-5
• Description: MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
• Manufacturer: AD [Analog Devices]

ADuC845/ADuC847/ADuC848
USER DOWNLOAD MODE (ULOAD)
Figure 28 shows that it is possible to use the 62 kbytes of
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 code.
However, most of the Flash/EE program memory can also be
written to during run time simply by entering ULOAD mode.
In ULOAD mode, the lower 56 kbytes of program memory can
be erased and reprogrammed by the user software as shown in
Figure 30. ULOAD mode can be used to upgrade the code in
the field via any user-defined download protocol. By configuring
the SPI port on the ADuC845/ADuC847/ADuC848 as a slave, it
is possible to completely reprogram the 56 kbytes of Flash/EE
program memory in under 5 s (see Application Note uC007,
“User Download Mode” at www.analog.com/microconverter).
Alternatively, ULOAD mode can be used to save data to the
56 kbytes of Flash/EE memory. This can be extremely useful in
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 of the 62 kbytes of Flash/EE program
memory (8 kbytes on the 32-kbyte parts) are programmable
only via serial download or parallel programming. This means
that this space appears as read-only to user code; therefore, it
cannot be accidentally erased or reprogrammed by erroneous
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 after
reset.
Programming the Flash/EE program memory via ULOAD
mode is described in the Flash/EE Memory Control SFR section
of ECON and also in Application Note uC007
(www.analog.com/microconverter).
Figure 30. Flash/EE Program Memory Map in ULOAD Mode (62-kbyte Part)
62 kBYTES
OF USER
MEMORY
PERMANENTLY EMBEDDED FIRMWARE ALLOWS
CODE
CODE TO BE DOWNLOADED TO ANY OF THE
62 kBYTES OF ON-CHIP PROGRAM MEMORY.
THE KERNEL PROGRAM APPEARS AS NOP
EMBEDDED DOWNLOAD/DEBUG KERNEL
INSTRUCTIONS TO USER CODE.
DOWNLOAD/DEBUG MODE VIA THE
KERNEL BUT IS READ ONLY WHEN
SPACE CAN BE PROGRAMMED IN
EITHER THE DOWNLOAD/DEBUG
ULOAD MODE) CAN PROGRAM
USER DOWNLOADER SPACE
USER BOOTLOADER SPACE
KERNEL OR USER CODE (IN
THE USER BOOTLOADER
EXECUTING USER CODE
THIS SPACE
56kBYTE
2kBYTE
6kBYTE
dFFFH
FFFFH
0000H
F800H
F7FFH
E000H
Rev. A | Page 50 of 108
The 32-kbyte memory parts have the user bootload space
starting at 6000H. The memory mapping is shown in Figure 31.
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.
Figure 31. Flash/EE Program Memory Map in ULOAD Mode (32-kbyte Part)
32 kBYTES
OF USER
MEMORY
PERMANENTLY EMBEDDED FIRMWARE ALLOWS
CODE
CODE TO BE DOWNLOADED TO ANY OF THE
32 kBYTES OF ON-CHIP PROGRAM MEMORY.
THE KERNEL PROGRAM APPEARS AS NOP
EMBEDDED DOWNLOAD/DEBUG KERNEL
INSTRUCTIONS TO USER CODE.
KERNEL OR USER CODE (IN ULOAD
DOWNLOAD/DEBUG MODE VIA THE
MODE) CAN PROGRAM THIS SPACE
KERNEL BUT IS READ ONLY WHEN
SPACE CAN BE PROGRAMMED IN
EITHER THE DOWNLOAD/DEBUG
USER DOWNLOADER SPACE
USER BOOTLOADER SPACE
THE USER BOOTLOADER
EXECUTING USER CODE
NOT AVAILABLE TO USER
24kBYTE
2kBYTE
8kBYTE
FFFFH
5FFFH
F800H
0000H
8000H
6000H