10 Memory Interface
10 – 30
contents of PMOVLAY as part of your interrupt service routine.
10.6.2
ADSP-2181 Data Memory Interface
The ADSP-2181 addresses 16K x 16-bit wide internal data memory and
two 8K x 16-bit wide external data memory overlays. All accesses to
internal data memory are completed in a single processor instruction
cycle. The DWAIT field of the Waitstate Control Register (shown in Figure
10.28) sets the number of waitstates for each access to data memory
overlays. Figure 10.29 shows the data memory map of the ADSP-2181.
The processor’s memory-mapped control/status registers are mapped
into the top locations of internal data memory, addresses 0x3FE0-0x3FFF.
Most of the ADSP-2181’s control registers correspond to those found on
other ADSP-21xx processors. Note that the ADSP-2181’s System Control
Register does not have the boot memory control fields found on other
ADSP-21xx processors. Also note that the Waitstate Control Register
Figure 10.29 ADSP-2181 Data Memory Map
Data Memory
Address
32 Memory-Mapped
Control Registers
0x3FFF
0x3FE0
Internal
8160 words
0x3FDF
0x2000
8K Internal
(DMOVLAY=0)
or
External 8K
(DMOVLAY=1,2)
0x1FFF
0x0000
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
IOWAIT0
IOWAIT1
IOWAIT2
IOWAIT3
DWAIT
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
DM(0x3FFE)
Wait State Control Register
Figure 10.28 ADSP-2181 Wait State Control Register