Analog Devices SHARC ADSP-21368 - Core Access to IOP Registers

ADSP-21368 SHARC Processor Hardware Reference 2-3
I/O Processor
• Serial peripheral interface ports (SPI)
• Input data port (IDP)
4. Enable DMA
• Set the applicable bits in the appropriate control registers
For peripheral specific DMA information, see the following sections.
• “External Port DMA” on page 2-35
• “Serial Port DMA” on page 2-40
• “Serial Peripheral Interface DMA” on page 2-42
• “UART DMA” on page 2-44
• “Memory-to-Memory DMA” on page 2-48
Core Access to IOP Registers
In certain cases, extra core cycles are needed to process register accesses.
The access cycles are shown in Table 2-1 and the registers are shown in
Table 2-2.
Table 2-1. I/O Processor Stall Conditions
Type Of Access Number of Core Cycles
Core write
1
1
Core read
1
2
Unconditional, isolated I/O processor register
write
2
1
Unconditional I/O processor register write after a
write
2
2 (back-to-back)
Unconditional I/O processor register read
2
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