ADSP-BF50x Blackfin Processor Hardware Reference
3-11
Chip Bus Hierarchy
Memory DMA transfers can result in repeated accesses to the same mem-
ory location. Because the memory DMA controller has the potential of
simultaneously accessing on-chip and off-chip memory, considerable
throughput can be achieved. The throughput rate for an on-chip/off-chip
memory access is limited by the slower of the two accesses.
In the case where the transfer is from on-chip to on-chip memory or from
off-chip to off-chip memory, the burst accesses cannot occur simultane-
ously. The transfer rate is then determined by adding each transfer plus an
additional cycle between each transfer.
Table 3-2
shows many types of 16-bit memory DMA transfers. In the
table, it is assumed that no other DMA activity is conflicting with ongoing
operations. The numbers in the table are theoretical values. These values
may be higher when they are measured on actual hardware due to a variety
of reasons relating to the device that is connected to the EBIU.
Table 3-2. Performance of DMA Access to External Memory
Source
Destination
Approximate SCLKs For n Words (from start of
DMA to interrupt at end)
16-bit internal burst
flash memory
1
1
For ADSP-BF50xF (flash memory) products only.
L1 data memory
(s * n + 2) + r * [(x + 1) * n + b * (n - 1)]
where:
•
s
is the number of setup/hold SCLK cycles
(minimum of 2)
•
r
is the ratio BCLK/SCLK (BCLK is the burst
clock frequency of the internal parallel burst
flash)
•
x
is the number of wait states cycles in
NORCLK
•
b
is the number of NORCLK cycles between
bursts
L1 data memory
L1 data memory
2n + 12
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...