Motorola DSP56301 - Manual (Page 97)

Bus Interface Unit (BIU) Registers
Core Configuration 4 -23
20–16 BDFW[4–0] 11111
(31 wait
states)
Bus Default Area Wait State Control
Defines the number of wait states (one through 31) inserted into each external
access to an area that is not defined by any of the AAR registers. The access type
for this area is SRAM only. These bits should not be programmed as zero since
SRAM memory access requires at least one wait state.
When four through seven wait states are selected, one additional wait state is
inserted at the end of the access. When selecting eight or more wait states, two
additional wait states are inserted at the end of the access. These trailing wait
states increase the data hold time and the memory release time and do not
increase the memory access time.
15–13 BA3W[2–0] 111
(7 wait states)
Bus Area 3 Wait State Control
Defines the number of wait states (one through seven) inserted in each external
SRAM access to Area 3 (DRAM accesses are not affected by these bits). Area 3 is
the area defined by AAR3.
Note: Do not program the value of these bits as zero since SRAM memory
access requires at least one wait state.
When four through seven wait states are selected, one additional wait state is
inserted at the end of the access. This trailing wait state increases the data hold
time and the memory release time and does not increase the memory access time.
12–10 BA2W[2–0] 111
(7 wait states)
Bus Area 2 Wait State Control
Defines the number of wait states (one through seven) inserted into each external
SRAM access to Area 2 (DRAM accesses are not affected by these bits). Area 2 is
the area defined by AAR2.
Note: Do not program the value of these bits as zero, since SRAM memory
access requires at least one wait state.
When four through seven wait states are selected, one additional wait state is
inserted at the end of the access. This trailing wait state increases the data hold
time and the memory release time and does not increase the memory access time.
9–5 BA1W[4–0] 11111
(31 wait
states)
Bus Area 1 Wait State Control
Defines the number of wait states (one through 31) inserted into each external
SRAM access to Area 1 (DRAM accesses are not affected by these bits). Area 1 is
the area defined by AAR1.
Note: Do not program the value of these bits as zero, since SRAM memory
access requires at least one wait state.
When four through seven wait states are selected, one additional wait state is
inserted at the end of the access. When selecting eight or more wait states, two
additional wait states are inserted at the end of the access. These trailing wait
states increase the data hold time and the memory release time and do not
increase the memory access time.
Table 4-9. Bus Control Register (BCR) Bit Definitions (Continued)
Bit
Number
Bit Name Reset Value Description