Contents
ix
10.4
BOOT MEMORY INTERFACE .................................................... 10–15
10.4.1
Boot Pages ................................................................................. 10–15
10.4.2
Powerup Boot & Software Reboot ........................................ 10–16
10.4.3
Boot Memory Access ............................................................... 10–17
10.4.4
Boot Loading Sequence ........................................................... 10–17
10.5
BUS REQUEST/GRANT .............................................................. 10–21
10.6
ADSP-2181 MEMORY INTERFACES ......................................... 10–23
10.6.1
ADSP-2181 Program Memory Interface ............................... 10–25
10.6.2
ADSP-2181 Data Memory Interface ...................................... 10–30
10.6.3
ADSP-2181 Byte Memory Interface....................................... 10–32
10.6.4
ADSP-2181 I/O Memory Space ............................................. 10–32
10.6.5
ADSP-2181 Composite Memory Select................................. 10–35
10.6.6
External Memory Read – Overlays & I/O Memory ........... 10–36
10.6.7
External Memory Write – Overlays & I/O Memory .......... 10–37
10.7
MEMORY INTERFACE SUMMARY (ALL PROCESSORS) ... 10–37
CHAPTER 11
DMA PORTS
11.1
OVERVIEW ...................................................................................... 11–1
11.2
BDMA PORT .................................................................................... 11–2
11.2.1
BDMA Port Functional Description ........................................ 11–4
11.2.2
BDMA Control Registers .......................................................... 11–4
11.2.3
Byte Memory Word Formats ................................................... 11–9
11.2.4
BDMA Booting ........................................................................... 11–9
11.2.4.1
Development Software Features for BDMA Booting . 11–11
11.3
IDMA PORT ................................................................................... 11–12
11.3.1
IDMA Port Pin Summary ....................................................... 11–12
11.3.2
IDMA Port Functional Description ....................................... 11–14
11.3.3
Modifying Control Registers for IDMA ............................... 11–16
11.3.4
IDMA Timing ........................................................................... 11–17
11.3.4.1
Address Latch Cycle.......................................................... 11–17
11.3.4.2
Long Read Cycle ................................................................ 11–18
11.3.4.3
Short Read Cycle ................................................................ 11–20
11.3.4.4
Long Write Cycle ............................................................... 11–21
11.3.4.5
Short Write Cycle ............................................................... 11–23
11.3.5
Boot Loading Through The IDMA Port ............................... 11–24
11.3.6
DMA Cycle Stealing, DMA Hold Offs, and
IACK
............. 11–25