8-10
ADSP-2126x SHARC Processor Hardware Reference
occurs in two cycles. In cycle one, the processor performs an
ALE
cycle,
driving the 16 bits of external address,
EA15–0
, onto the 16-bit parallel
port bus (pins
AD15–0
), allowing the external latch to hold this address. In
the second cycle, the processor either drives or receives the 16 bits of
external data (
ED15–0
) through the 16-bit parallel port bus (pins
AD15–0
).
This pattern repeats until the transfer completes.
However, a special case occurs when the external address modifier is zero,
(
EMPP
= 0). In this case, the external address is latched only once, using the
ALE
cycle before the first data transfer. After the address has been latched
externally, the processor continues receiving and sending 16-bit data on
AD15–0
until the transfer completes. This mode can be used with external
FIFOs and high speed A/D and D/A converters and offers the maximum
throughput available on the parallel port (132 Mbyte/sec).
shows the connection diagram in 16-bit mode.
Figure 8-3. External Transfer—16-bit Mode
LATCH
ADSP-2126x
ALE
RD
WR
AD[15-0]
DATA[17-0]
ALE
Q[15-0]
ADDR[23-8]
RD
WR
SRAM
DATA[7-0]
180
⍀
68
⍀
CE
CE
SRAMCE
FLASHCE
16
16
16
FLASH
Содержание ADSP-21261 SHARC
Страница 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Страница 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Страница 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Страница 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Страница 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...