AD73422BB-40 Analog Devices Inc, AD73422BB-40 Datasheet - Page 27

• Manufacturer Part Number: AD73422BB-40
• Manufacturer: Analog Devices Inc

Specifications of AD73422BB-40

• Single Supply Voltage (typ): 3.3V
• Single Supply Voltage (min): 3V
• Single Supply Voltage (max): 3.6V
• Package Type: BGA
• Lead Free Status / RoHS Status: Not Compliant

MEMORY ARCHITECTURE
The AD73422 provides a variety of memory and peripheral
interface options. The key functional groups are Program
Memory, Data Memory, Byte Memory and I/O. Refer to the
following figures and tables for PM and DM memory alloca-
tions in the AD73422.
PROGRAM MEMORY
Program Memory (Full Memory Mode) is a 24-bit-wide
space for storing both instruction op codes and data. The
AD73422-80 has 16K words of Program Memory RAM on chip
(the AD73422-40 has 8K words of Program Memory RAM on
chip), and the capability of accessing up to two 8K external
memory overlay spaces using the external data bus.
Program Memory (Host Mode) allows access to all internal
memory. External overlay access is limited by a single external
address line (A0). External program execution is not available in
host mode due to a restricted data bus that is 16 bits wide only.
PMOVLAY
0
1
2
INTERNAL
MEMORY
REV. 0
EXTERNAL
MEMORY
PROGRAM MEMORY
PMOVLAY = 1 OR 2
ACCESSIBLE WHEN
PM (MODE B = 0)
0x0000 – 0x1FFF
8K EXTERNAL
8K INTERNAL
PMOVLAY = 0
8K INTERNAL
ACCESSIBLE
AT ADDRESS
PMOVLAY = 0
ACCESSIBLE WHEN
PMOVLAY = 1
MODE B = 0
ALWAYS
OR
ACCESSIBLE WHEN
PMOVLAY = 2
Figure 15. Program Memory Map
Memory
Internal
External
Overlay 1
External
Overlay 2
Table XXII. PMOVLAY Bits
ADDRESS
0x2000–
0x3FFF
0x3FFF
0x1FFF
0x0000
0x2000
0x2000–
0x3FFF
0x2000–
0x3FFF
A13
Not Applicable Not Applicable
0
1
2
2
INTERNAL
MEMORY
1
2
WHEN MODE B = 1, PMOVLAY MUST BE SET TO 0
SEE TABLE III FOR PMOVLAY BITS
EXTERNAL
MEMORY
PM (MODE B = 1)
ACCESSIBLE WHEN
PROGRAM MEMORY
ACCESSIBLE WHEN
PMOVLAY = 0
PMOVLAY = 0
8K EXTERNAL
PMOVLAY = 0
RESERVED
8K INTERNAL
MODE B = 1
A12:0
13 LSBs of Address
Between 0x2000
and 0x3FFF
13 LSBs of Address
Between 0x2000
and 0x3FFF
RESERVED
1
0x2000–
0x3FFF
ADDRESS
0x3FFF
0x2000
0x1FFF
0x0000
0x0000–
0x1FFF
2
–27–
DATA MEMORY
Data Memory (Full Memory Mode) is a 16-bit-wide space
used for the storage of data variables and for memory-mapped
control registers. The AD73422-80 has 16K words on Data
Memory RAM on chip (the AD73422-40 has 8K words on Data
Memory RAM on chip), consisting of 16,352 user-accessible
locations in the case of the AD73422-80 (8,160 user-accessible
locations in the case of the AD73422-40) and 32 memory-
mapped registers. Support also exists for up to two 8K external
memory overlay spaces through the external data bus. All inter-
nal accesses complete in one cycle. Accesses to external memory
are timed using the wait states specified by the DWAIT register.
Data Memory (Host Mode) allows access to all internal memory.
External overlay access is limited by a single external address
line (A0). The DMOVLAY bits are defined in Table XXIII.
DMOVLAY Memory
0
1
2
I/O Space (Full Memory Mode)
The AD73422 supports an additional external memory space
called I/O space. This space is designed to support simple con-
nections to peripherals (such as data converters and external
registers) or to bus interface ASIC data registers. I/O space
supports 2048 locations of 16-bit wide data. The lower eleven
bits of the external address bus are used; the upper three bits are
undefined. Two instructions were added to the core ADSP-2100
Family instruction set to read from and write to I/O memory
space. The I/O space also has four dedicated 3-bit wait state
registers, IOWAIT0-3, that specify up to seven wait states to be
automatically generated for each of four regions. The wait states
act on address ranges as shown in Table XXIV.
INTERNAL
MEMORY
EXTERNAL
MEMORY
ACCESSIBLE WHEN
DATA MEMORY
0
x
AT ADDRESS
DMOVLAY = 0
ACCESSIBLE
2000 – 0
ACCESSIBLE WHEN
DMOVLAY = 1
ALWAYS
Internal
External
Overlay 1
External
Overlay 2
Figure 16. Data Memory Map
ACCESSIBLE WHEN
DMOVLAY = 2
Table XXIII. DMOVLAY Bits
x
3FFF
0
0
x
x
0000–
1FFF
A13
Not Applicable Not Applicable
0
1
0
0
x
x
0000–
1FFF
0
0
x
x
0000–
1FFF
DMOVLAY = 1, 2
DATA MEMORY
EXTERNAL 8K
8K INTERNAL
DMOVLAY = 0
32 MEMORY
REGISTERS
INTERNAL
MAPPED
A12:0
13 LSBs of Address
Between 0x2000
and 0x3FFF
13 LSBs of Address
Between 0x2000
and 0x3FFF
WORDS
AD73422
8160
OR
ADDRESS
0
0
0
0
0
0
x
x
x
x
x
x
3FFF
3FE0
3FDF
1FFF
2000
0000