Contents
viii
CHAPTER 9
SYSTEM INTERFACE
9.1
OVERVIEW ........................................................................................ 9–1
9.2
CLOCK SIGNALS.............................................................................. 9–3
9.2.1
Synchronization Delay ................................................................ 9–3
9.2.2
1x & 1/2x Clock Considerations ............................................... 9–4
9.3
RESET
........................................................................................ 9–4
9.4
SOFTWARE-FORCED REBOOTING ............................................. 9–4
9.4.1
ADSP-2181 Register Values For BDMA Booting .................. 9–13
9.5
EXTERNAL INTERRUPTS ............................................................. 9–14
9.5.1
Interrupt Sensitivity .................................................................. 9–14
9.6
FLAG PINS ...................................................................................... 9–15
9.7
POWERDOWN ................................................................................ 9–17
9.7.1
Powerdown Control .................................................................. 9–18
9.7.2
Entering Powerdown ................................................................ 9–19
9.7.3
Exiting Powerdown ................................................................... 9–20
9.7.3.1
Ending Powerdown With The
PWD
Pin .......................... 9–20
9.7.3.2
Ending Powerdown With The
RESET
Pin ....................... 9–21
9.7.4
Startup Time After Powerdown .............................................. 9–21
9.7.4.1
Systems Using An External TTL/CMOS Clock .............. 9–21
9.7.4.2
Systems Using A Crystal/Internal Oscillator .................. 9–22
9.7.5
Operation During Powerdown ................................................ 9–23
9.7.5.1
Interrupts & Flags ................................................................ 9–23
9.7.5.2
SPORTS ................................................................................. 9–23
9.7.5.3
HIP During Powerdown..................................................... 9–24
9.7.5.4
IDMA Port During Powerdown (ADSP-2181) ................ 9–25
9.7.5.5
BDMA Port During Powerdown (ADSP-2181) ............... 9–26
9.7.5.6
Analog Interface (ADSP-21msp5x) ................................... 9–26
9.7.6
Conditions For Lowest Power Consumption ........................ 9–26
9.7.7
PWDACK Pin ............................................................................. 9–29
9.7.8
Using Powerdown As A Non-Maskable Interrupt ............... 9–30
CHAPTER 10
MEMORY INTERFACE
10.1
OVERVIEW ...................................................................................... 10–1
10.2
PROGRAM MEMORY INTERFACE ............................................ 10–3
10.2.1
External Program Memory Read/Write ................................ 10–3
10.2.2
Program Memory Maps............................................................ 10–5
10.2.3
ROM Program Memory Maps ................................................. 10–6
10.3
DATA MEMORY INTERFACE ................................................... 10–10
10.3.1
External Data Memory Read/Write ..................................... 10–10
10.3.2
Data Memory Maps ................................................................. 10–11
10.3.3
Memory-Mapped Peripherals................................................ 10–14