ADSP-2126x SHARC Processor Hardware Reference
8-17
Parallel Port
This 24-bit register contains the number of words in external
memory to be transferred via DMA.
Parallel Port External Setup Registers
The following registers must be initialized for both core-driven and
DMA-driven transfers.
• Parallel Port DMA External Index Address (
EIPP
) register
This 24-bit register contains the external memory byte address used
for core-driven and DMA driven transfers.
• Parallel Port External Address Modifier (
EMPP
) register
This 2-bit register contains the external memory DMA address
modifier. It supports only +1, 0, –1. After each data cycle, the
EIPP
register is modified by this value.
Using the Parallel Port
There are a number of considerations to make when interfacing to parallel
external devices. This section describes the different the ways that the par-
allel port can be used to access external devices. Considerations for
choosing between an 8-bit and a 16-bit wide interface are discussed in
“Comparison of 16-Bit and 8-Bit SRAM Modes” on page 8-11
External parallel devices can be accessed in two ways, either using
DMA-driven transfers or core-driven transfers. DMA transfers are per-
formed in the background by the I/O Processor and are generally used to
move blocks of data. To perform DMA transfers, the address, word-count,
and address-modifier are specified for both the source and destination buf-
fers (one internal, one external). Once initiated, (by setting
PPEN
= 1 and
PPDEN
= 1), the IOP performs the specified transfer in the background
without further core interaction. The main advantage of DMA transfers
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...