
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
Information Manual
Software Architecture
April 1998
3-56
DRAFT COPY
Lucent Technologies Inc.
3.6 Power Management
(continued)
3.6.2 STOP Pin
Assertion (active-low) of the STOP pin has the same effect as setting the NOCK bit in the powerc register. The
internal processor clock is synchronously disabled until the STOP pin is returned high. If the STOP pin is returned
high, program execution continues from where it left off without any loss of state. No chip reset is required. For the
DSP1627/28/29, the PLL remains running, if enabled, during STOP assertion.
3.6.3 The pllc Register Bits (DSP1627/28/29 Only)
The PLLEN bit of the pllc register can be used to power down the clock synthesizer circuitry. Before shutting down
the clock synthesizer circuitry, the system clock should be switched to either CKI by using the PLLSEL bit of pllc or
to the ring oscillator by using the SLOWCKI bit of powerc.
3.6.4 AWAIT Bit of the alf Register
Setting the AWAIT bit of the alf register causes the processor to go into the standard sleep state or power-saving
standby mode. Operation of the AWAIT bit is unchanged from the DSP1610. In this mode, only the minimum cir-
cuitry required to process an incoming interrupt remains active. An interrupt returns the processor to the previous
state, and program execution continues. The action resulting from setting the AWAIT bit and the action resulting
from setting bits in the powerc register are mostly independent. As long as the processor is receiving a clock,
whether slow or fast, the DSP can be put into standard sleep mode with the AWAIT bit. If the AWAIT bit is set, the
STOP pin can be used to stop and later restart the processor clock returning to the standard sleep state. If the pro-
cessor clock is not running, however, the AWAIT bit cannot be set. If executing code with two or more wait-states,
it is recommended that the alf register be set from within the cache to prevent any pending interrupt from being ser-
viced until after the DSP enters the AWAIT state.
Содержание DSP1611
Страница 18: ...Chapter 1 Introduction...
Страница 27: ...Chapter 2 Hardware Architecture...
Страница 52: ...Chapter 3 Software Architecture...
Страница 116: ...Chapter 4 Instruction Set...
Страница 154: ...Chapter 5 Core Architecture...
Страница 176: ...Chapter 6 External Memory Interface...
Страница 208: ...Chapter 7 Serial I O...
Страница 237: ...Chapter 8 Parallel I O DSP1617 Only...
Страница 261: ...Chapter 9 Parallel Host Interface PHIF DSP1611 18 27 28 29 Only...
Страница 275: ...Chapter 10 Bit I O Unit...
Страница 284: ...Chapter 11 JTAG Test Access Port...
Страница 306: ...Chapter 12 Timer...
Страница 313: ...Chapter 13 Bit Manipulation Unit...
Страница 325: ...Chapter 14 Error Correction Coprocessor DSP1618 28 Only...
Страница 350: ...Chapter 15 Interface Guide...
Страница 367: ...Appendix A Instruction Encoding...
Страница 379: ...Appendix B Instruction Set Summary...
Страница 381: ...aD extractz aS IM16 B 52 aD insert aS arM B 53 aD insert aS IM16 B 54 aD aS aaT B 55...
Страница 437: ...Index...