ADUC7023 Analog Devices, ADUC7023 Datasheet - Page 21

• Manufacturer Part Number: ADUC7023
• Description: Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI MCU
• Manufacturer: Analog Devices

Specifications of ADUC7023

• Mcu Core: ARM7 TDMI
• Mcu Speed (mips): 40
• Sram (bytes): 8192Bytes
• Gpio Pins: 20
• Adc # Channels: 12
• Other: PWM

MEMORY ORGANIZATION
The ADuC7023 incorporates two separate blocks of memory:
8 kB of SRAM and 64 kB of on-chip Flash/EE memory; 62 kB of
on-chip Flash/EE memory is available to the user, and the
remaining 2 kB are reserved for the factory configured boot
page. These two blocks are mapped as shown in Figure 15.
By default, after a reset, the Flash/EE memory is mirrored at
Address 0x00000000. It is possible to remap the SRAM at
Address 0x00000000 by clearing Bit 0 of the Remap MMR. This
remap function is described in more detail in the Flash/EE
Memory section.
MEMORY ACCESS
The ARM7 core sees memory as a linear array of the 2
location where the different blocks of memory are mapped as
outlined in Figure 15.
The ADuC7023 memory organizations are configured in little
endian format, which means that the least significant byte is
located in the lowest byte address, and the most significant byte
is in the highest byte address.
BIT 31
0xFFFF0000
0x00080000
0x00010000
0x00000000
BYTE 3
B
7
3
.
.
.
0xFFFFFFFF
0x0008FFFF
0x0000FFFF
0x00011FFF
Figure 15. Physical Memory Map
BYTE 2
Figure 16. Little Endian Format
A
6
2
.
.
.
32 BITS
BYTE 1
MMRs
RESERVED
FLASH/EE
RESERVED
SRAM
REMAPPABLE MEMORY SPACE
(FLASH/EE OR SRAM)
9
5
1
.
.
.
BYTE 0
8
4
0
.
.
.
BIT 0
0xFFFFFFFF
0x00000004
0x00000000
32
byte
Rev. B | Page 21 of 96
FLASH/EE MEMORY
The total 64 kB of Flash/EE memory is organized as 32k × 16 bits;
31k × 16 bits is user space and 1 k × 16 bits is reserved for the
on-chip kernel. The page size of this Flash/EE memory is 512 bytes.
62 kilobytes of Flash/EE memory are available to the user as
code and nonvolatile data memory. There is no distinction
between data and program because ARM code shares the same
space. The real width of the Flash/EE memory is 16 bits, which
means that in ARM mode (32-bit instruction), two accesses to
the Flash/EE are necessary for each instruction fetch. It is,
therefore, recommended to use Thumb mode when executing
from Flash/EE memory for optimum access speed. The
maximum access speed for the Flash/EE memory is 41.78 MHz
in Thumb mode and 20.89 MHz in full ARM mode. More
details about Flash/EE access time are outlined later in the
Execution Time from SRAM and Flash/EE section.
SRAM
Eight kilobytes of SRAM are available to the user, organized as
2k × 32 bits, that is, two words. ARM code can run directly
from SRAM at 41.78 MHz, given that the SRAM array is
configured as a 32-bit wide memory array. More details about
SRAM access time are outlined later in the Execution Time
from SRAM and Flash/EE section.
MEMORY MAPPED REGISTERS
The memory mapped register (MMR) space is mapped into the
upper two pages of the memory array and accessed by indirect
addressing through the ARM7 banked registers.
The MMR space provides an interface between the CPU and
all on-chip peripherals. All registers, except the core registers,
reside in the MMR area. All shaded locations shown in Figure 17
are unoccupied or reserved locations and should not be
accessed by user software. Table 10 to Table 23 show the full
MMR memory map.
The access time for reading from or writing to an MMR depends
on the advanced microcontroller bus architecture (AMBA) bus
used to access the peripheral. The processor has two AMBA
buses: advanced high performance bus (AHB) used for system
modules and advanced peripheral bus (APB) used for lower
performance peripheral. Access to the AHB is one cycle, and
access to the APB is two cycles. All peripherals on the ADuC7023
are on the APB except the Flash/EE memory and the GPIOs.
ADuC7023