ADSP-2126x SHARC Processor Hardware Reference
8-9
Parallel Port
8-Bit Mode
An
ALE
cycle always precedes the first transfer of data after the parallel port
is enabled. During
ALE
cycles for 8-bit mode, the upper 16 bits of the
external address (
EA23–8
) are driven on the 16-bit parallel port bus (pins
AD15–0
). In data cycles (reads and writes), the processor drives the lower 8
bits of address
EA7–0
on
AD15–8
. The 8 bits of external data,
ED7–0
, that
are provided by
AD7–0
, are sampled by the
RD
/
WR
signal respectively. The
processor continues to receive and or send data with the same
ALE
cycle
until the upper 16 bits of external address differ from the previous access.
For consecutive accesses (
EMPP
= 1), this occurs once every 256 cycles.
shows the connection diagram for the 8-bit mode.
Eight-bit mode enables a larger external address range.
16-Bit Mode
In 16-bit mode, the external address range is
EA15–0
(64K addressable
16-bit words). For a nonzero stride value (
EMPP
= 0), the transfer of data
Figure 8-2. External Transfer—8-bit Mode
LATCH
ADSP-2126x
AD[7-0]
ALE
RD
WR
AD[15-8]
ADDR[7-0]
DATA[7-0]
D[7-0]
ALE
D[15-8]
Q[15-0]
ADDR[23-8]
RD
WR
SRAM
DATA[7-0]
180
⍀
68
⍀
CE
CE
SRAMCE
FLASHCE
8
8
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 ...