ADUC834 Analog Devices, ADUC834 Datasheet - Page 30

• Manufacturer Part Number: ADUC834
• Description: Precision Analog Microcontroller: 1MIPS 8052 MCU + 62kB Flash + 16/24-Bit ADC + 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC834

• Mcu Core: 8052
• Mcu Speed (mips): 1
• Sram (bytes): 2304Bytes
• Gpio Pins: 34
• Adc # Channels: 4
• Other: PWM

ADuC834
Flash/EE Program Memory
The ADuC834 contains a 64 Kbyte array of Flash/EE program
memory. The lower 62 Kbytes of this program memory is avail-
able to the user, and can be used for program storage or indeed
as additional NV data memory.
The upper 2 Kbytes of this Flash/EE program memory array
contain permanently embedded firmware, allowing in circuit serial
download, serial debug and nonintrusive single pin emulation.
These 2 Kbytes of embedded firmware also contain a power-on
configuration routine that downloads factory calibrated coeffi-
cients to the various calibrated peripherals (ADC, temperature
sensor, current sources, bandgap references and so on).
This 2 Kbyte embedded firmware is hidden from user code.
Attempts to read this space will read 0s, i.e., the embedded firmware
appears as NOP instructions to user code.
In normal operating mode (power up default) the 62 Kbytes of
user Flash/EE program memory appear as a single block. This
block is used to store the user code as shown in Figure 17.
In Normal Mode, the 62 Kbytes of Flash/EE program memory
can be programmed programmed in two ways, namely:
(1) Serial Downloading (In-Circuit Programming)
The ADuC834 facilitates code download via the standard UART
serial port. The ADuC834 will enter Serial Download mode
after a reset or power cycle if the PSEN pin is pulled low through
an external 1 kΩ resistor. Once in serial download mode, the
hidden embedded download kernel will execute. This allows the
user to download code to the full 62 Kbytes of Flash/EE program
memory while the device is in circuit in its target application
hardware.
A PC serial download executable is provided as part of the
ADuC834 QuickStart development system. Appliction Note
uC004 fully describes the serial download protocol that is used
by the embedded download kernel. This Appliction Note is
available at www.analog.com/microconverter.
PERMANENTLY EMBEDDED FIRMWARE ALLOWS CODE
ON-CHIP PROGRAM MEMORY. THE KERNEL PROGRAM
TO BE DOWNLOADED TO ANY OF THE 62 KBYTES OF
AVAILABLE TO THE USER. ALL OF THIS SPACE CAN
APPEARS AS ‘NOP’ INSTRUCTIONS TO USER CODE.
62 KBYTES OF FLASH/EE PROGRAM MEMORY IS
EMBEDDED DOWNLOAD/DEBUG KERNEL OR IN
BE PROGRAMMED FROM THE PERMANENTLY
Figure 17. Flash/EE Program Memory Map in
Normal Mode
EMBEDDED DOWNLOAD/DEBUG KERNEL
PARALLEL PROGRAMMING MODE.
USER PROGRAM MEMORY
62 KBYTE
2 KBYTE
FFFFH
F800H
F7FFH
0000H
–30–
(2) Parallel Programming
The parallel programming mode is fully compatible with conven-
tional third party Flash or EEPROM device programmers. A block
diagram of the external pin configuration required to support parallel
programming is shown in Figure 18. In this mode, Ports 0, and 2
operate as the external address bus interface, P3 operates as the
external data bus interface and P1.0 operates as the Write Enable
strobe. Port 1.1, P1.2, P1.3, and P1.4 are used as a general
configuration port that configures the device for various program
and erase operations during parallel programming.
Table XIII. Flash/EE Memory Parallel Programming Modes
P1.4
0
1
1
0
1
0
1
1
All other codes
User Download Mode (ULOAD)
In Figure 17 we can see that it was 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 of the Flash/EE memory is
read only to user code.
However, the Flash/EE program memory can also be written to
during runtime simply by entering ULOAD mode. In ULOAD
mode, the lower 56 Kbytes of program memory can be erased
and reprogrammed by user software as shown in Figure 19.
ULOAD mode can be used to upgrade your code in the field via
any user defined download protocol. Configuring the SPI port on
the ADuC834 as a slave, it is possible to completely reprogram
the 56 Kbytes of Flash/EE program memory in only 5 seconds.
See Application Note uC007.
SEQUENCE
PROGRAM MODE
(SEE TABLE XIII)
Figure 18. Flash/EE Memory Parallel Programming
ENTRY
Port 1 Pins
P1.3
0
0
0
0
0
0
1
1
COMMAND
ENABLE
GND
GND
V
DD
P1.2
0
0
1
1
1
1
0
0
5V
P1.1
0
1
0
0
1
1
0
1
P1.1 -> P1.4
P1.0
EA
PSEN
RESET
V
GND
DD
ADuC834
Programming Mode
Erase Flash/EE Program,
Data, and Security Modes
Read Device Signature/ID
Program Code Byte
Program Data Byte
Read Code Byte
Read Data Byte
Program Security Modes
Read/Verify Security Modes
Redundant
P1.5 -> P1.7
P0
P3
P2
PROGRAM
DATA
(D0–D7)
PROGRAM
ADDRESS
(A0–A13)
(P2.0 = A0)
(P1.7 = A13)
TIMING
REV. A