VR4102 datasheet(421/701 Pages) NEC

421 / 701 page

CHAPTER 20 AIU (AUDIO INTERFACE UNIT)

421

20.3 OPERATION SEQUENCE

20.3.1 Output (Speaker)

Set conversion rate (0x0B00 016A: SCNVR = arbitrary)

Set output data area to DMAAU

DMA enable in DCU

Set D/A converter’s Vref to ON (0x0B00 0168: DAENAIU = 1)

Wait for Vref resistor stabilization time (about 5

Ps) (use the RTC counter)

Even if speaker power is set to ON without waiting for Vref resistor stabilization time and speaker

operation is enabled, speaker output starts after the period calculated with the formula below.

5 + 1/conversion rate (44.1, 22.05, 11.025, or 8) (

Ps)

Set speaker power ON via GPIO.

Speaker operation enable (0x0B00 017A: AIUSEN = 1)

DMA request

Receive acknowledge and DMA data from DMA

0x0B00 0178: SDMAV = SODATV = 1

Output 10-bit data (0x0B00 0166: SODAT) to D/A converter

SODATV = 0, SDMAV = 1

Send SDMADATREG data to SODATREG

SODATV = 1, SDMAV = 0

Output DMA request and store the second data to SDMADATREG

SODATV = 1, SDMAV = 1

Refresh data at each conversion timing interval (becomes SIDLEINTR = 1 when DMA is slow and

SODATV = 0 during conversion timing interval, and (mute) interrupt occurs)

DMA page boundary interrupt occurs at page boundary

Page interrupt is cleared when output continues

Speaker operation to disable (0x0B00 017A: AIUSEN = 0)

Set speaker power OFF via GPIO.

10. Set D/A converter’s Vref to OFF (0x0B00 0168: DAENAIU = 0)

11. DMA disable in DCU

VR4102 Datasheet(PDF) 421 Page - NEC