AK2303LV Datasheet, PDF (16/41 Pages) Asahi Kasei Microsystems – Dual PCM CODEC for PBX Analog Line Card

ASAHI KASEI
RESET
[AK2303LV]
Power on Reset
AK2303LV automatically generates the internal reset pulse which resets all the circuit that is necessary to start the
initialization after the power on reset. The CPU registers are set to the default value.
After the internal reset pulse is generated, CODEC Ch0/Ch1 starts the initialization procedure by being fed FS signal, and it
takes 180ms( typ.), 350ms(max) to complete the initialization after the detection of power on.
Power up slope to enable the Power-on Reset
When power-up slope is no longer than 50ms(=5tau:tau is time constant), Power On Reset works normally.
When the time is longer than 50ms, Power On Reset is not activated and no internal registers are initialized. In
this case all registers must be written through CPU interface.
NOTE) For stable operation after power up, we recommend to write all register value through CPU interface after power up.
Recommended start up procedure
The following start up procedure is recommended when AK2303LV is going to power up.
Power up
Wait 200ms
*In case of VDD rising time
=50ms(=5tau)
- FS=”L”
- BCLK=”L”
- MUTE 0/1=”L”
When 1stFS and BCLK are set to “L”, CODEC
ch0,ch1 dose not interface with external
devices.
Write data to the internal
register through serial I/F
- Write data to the internal register
before CODEC starts working.
Supply FS and BCLK
Wait 130ms
CODEC starts working
- CODEC Initialization starts.
- CODEC Initialization complete.
- MUTE 0/1=”H”
2303-E-00
16
2001/09