ACS422A68TAGZBX8 IDT, ACS422A68TAGZBX8 Datasheet - Page 72

• Manufacturer Part Number: ACS422A68TAGZBX8
• Description: Interface - CODECs
• Manufacturer: IDT

Specifications of ACS422A68TAGZBX8

• Rohs: yes
• Part # Aliases: IDTACS422A68TAGZBX8

ACS422x68
LOW-POWER, HIGH-FIDELITY, INTEGRATED CODEC
©2011 INTEGRATED DEVICE TECHNOLOGY, INC.
6. AUDIO CLOCK GENERATION
6.1.
6.2.
The ACS422x68 utilizes internal PLLs to generate the audio master clocks (ACLK) at 56.448MHz (22.5792MHz *2.5)
and 61.44MHz (24.576 *2.5). It then generates audio sample rates directly from the audio master clocks. The ADC and
DAC do not need to run at the same sample rate unless they are sharing BCLK and LRCLK pins. Disable the appropri-
ate converters before programming the mode or rate, especially if the DAC and ADC are programmed to share the
same BCLK and LRCLK. After changing rate, a delay of up to 5mS may be needed for the part to properly lock PLLs,
flush filters, etc .
R23 (17h)
ADC Sample Rate
Control
(ADCSR)
Register Address
Internal Clock Generation (ACLK)
6.1.1.
ACLK Clocking and Sample Rates
In addition to providing external clocks, the PLL block will also provide two clocks for the audio por-
tion of the device. They are
•
•
External MCLK
The ACS422x68 is designed to use an external clock (MCLK) whose frequency is 11.2896MHz
when playing 44.1KHz audio or 12.288MHz when playing 48KHz audio. Other frequencies are
acceptable, but please contact your IDT support representative for assistance in ensuring compati-
bility. An active MCLK is required when power is applied for proper operation. MCLK is required for
I2S communication.
122.880 MHz (2560 x 48 KHz)
112.896 (2560 x 44.1 KHz)
Bit
7:6
4:3
2:0
5
ABCM[1:0]
ABM[2:0]
ABR[1:0]
RSVD
Label
Table 79. ADCSR Register
Type
RW
RW
RW
R
Default
72
010
00
10
0
ADC Bit Clock Mode (for data interface ADCBCLK
generation in master mode)
00 = Auto
01 = 32x fs
10 = 40x fs
11 = 64x fs
Reserved
ADC Base Rate
00 = 32KHz
01 = 44.1KHz
10 = 48KHz
11 = Reserved
ADC Base Rate Multiplier
000 = 0.25x
001 = 0.50x
010 = 1x
011 = 2x
100-111 = Reserved
Description
ACS422X68
V1.6 01/13