ADUC816 Analog Devices, ADUC816 Datasheet - Page 23

• Manufacturer Part Number: ADUC816
• Description: Precision Analog Microcontroller: 1MIPS 8052 MCU + 8kB Flash + Dual 16-Bit ADC + 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC816

• Mcu Core: 8052
• Mcu Speed (mips): 1.3
• Sram (bytes): 256Bytes
• Gpio Pins: 34
• Adc # Channels: 4

REV. A
Reset initializes the stack pointer to location 07 hex and increments
it once to start from locations 08 hex which is also the first regis-
ter (R0) of register bank 1. Thus, if one is going to use more
than one register bank, the stack pointer should be initialized to an
area of RAM not used for data storage.
The SFR space is mapped to the upper 128 bytes of internal data
memory space and accessed by direct addressing only. It provides
an interface between the CPU and all on-chip peripherals. A block
diagram showing the programming model of the ADuC816 via
the SFR area is shown in Figure 16. A complete SFR map is shown
in Figure 17.
OVERVIEW OF MCU-RELATED SFRS
Accumulator SFR
ACC is the Accumulator register and is used for math operations
including addition, subtraction, integer multiplication and division,
and Boolean bit manipulations. The mnemonics for accumulator-
specific instructions refer to the Accumulator as A.
B SFR
The B register is used with the ACC for multiplication and divi-
sion operations. For other instructions it can be treated as a
general-purpose scratchpad register.
Stack Pointer SFR
The SP register is the stack pointer and is used to hold an internal
RAM address that is called the
is incremented before data is stored during PUSH and CALL
executions. While the Stack may reside anywhere in on-chip
RAM, the SP register is initialized to 07H after a reset. This causes
the stack to begin at location 08H.
Data Pointer
The Data Pointer is made up of three 8-bit registers, named
DPP (page byte), DPH (high byte) and DPL (low byte). These
are used to provide memory addresses for internal and external
code access and external data access. It may be manipulated as
a 16-bit register (DPTR = DPH, DPL), although INC DPTR
instructions will automatically carry over to DPP, or as three
independent 8-bit registers (DPP, DPH, DPL).
FLASH/EE PROGRAM
REPROGRAMMABLE
ELECTRICALLY
COMPATIBLE
NONVOLATILE
256 BYTES
MEMORY
8 KBYTE
CORE
8051-
RAM
FUNCTION
REGISTER
128-BYTE
SPECIAL
AREA
REPROGRAMMABLE
SIGMA-DELTA ADCs
FLASH/EE DATA
OTHER ON-CHIP
ELECTRICALLY
TEMPERATURE
NONVOLATILE
PERIPHERALS
12-BIT DAC
SERIAL I/O
SOURCES
CURRENT
The SP register
640-BYTE
MEMORY
SENSOR
DUAL
WDT
PSM
PLL
TIC
Program Status Word SFR
The PSW register is the Program Status Word which contains
several bits reflecting the current status of the CPU as detailed in
Table I.
SFR Address
Power ON Default Value
Bit Addressable
Bit
7
6
5
4
3
2
1
0
Power Control SFR
The Power Control (PCON) register contains bits for power-
saving options and general-purpose status flags as shown in
Table II.
SFR Address
Power ON Default Value
Bit Addressable
Bit
7
6
5
4
3
2
1
0
S
C
M
O
Y
D
S
E
A
R
C
I
Table II. PCON SFR Bit Designations
P
Table I. PSW SFR Bit Designations
Name
CY
AC
F0
RS1
RS0
OV
F1
P
Name
SMOD
SERIPD
INT0PD
ALEOFF
GF1
GF0
PD
IDL
D
I
N
F
T
0
0
P
D
A
R
L
E
S
O
1
F
F
Description
Carry Flag
Auxiliary Carry Flag
General-Purpose Flag
Register Bank Select Bits
RS1
0
0
1
1
Overflow Flag
General-Purpose Flag
Parity Bit
Description
Double UART Baud Rate
I
Enable
INT0 Power-Down Interrupt
Enable
Disable ALE Output
General-Purpose Flag Bit
General-Purpose Flag Bit
Power-Down Mode Enable
Idle Mode Enable
2
C/SPI Power-Down Interrupt
R
G
S
F
D0H
No
00H
Yes
87H
00H
1
0
RS0
0
1
0
1
O
G
F
V
0
Selected Bank
0
1
2
3
F
P
D
1
I
P
D
L