External Port Throughput
3-118 ADSP-214xx SHARC Processor Hardware Reference
DDR2 Throughput
The following sections provide information needed to configure the
DDR2 interface for the desired throughput.
DMA Throughput
Table 3-31 provides approximate throughput information with the pro-
cessor core running at 400 MHz for DMA-driven reads and writes of
external DDR2 memory. The throughput numbers shown are measured
by running chained DMA with four TCBs (with 256 32-bit words per
transfer block).
For the analysis, 16 bit DDR2 is used (t
FAW
=10, t
RRD
=2, t
RTP
=2,
t
MRD
=3, t
RCD
=3, t
WTR
=1, t
RP
=3, t
RAS
=8, CL=4, AL=4, t
WR
=4).
Throughput is calculated by measuring time between the instant when
DMA is enabled and instant when DMA completion ISR is entered.
Core Throughput
Table 3-32 provides approximate throughput information with the pro-
cessor core running at 400 MHz for core-driven reads and writes of
Table 3-31. DMA Throughput, 400 MHz Core Clock
Operation DDR2 Clock Clock Ratio Throughput
DMA Reads
133 MHz 1:3 473M bytes/sec.
200 MHz 1:2 700M bytes/sec.
DMA Writes
133 MHz 1:3 481M bytes/sec.
200 MHz 1:2 732M bytes/sec.
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