AK7755EN_16 Datasheet, PDF (66/109 Pages) Asahi Kasei Microsystems – DSP with Mono ADC Stereo CODEC + Mic/Lineout Amp

[AK7755]
■ μP Interface Setting and Pin Status
SPI or I²C bus interface mode can be selected by the I2CSEL pin. Pin statuses that are changed by I2CSEL
pin setting are shown below.
I2CSEL
PDN
SO/SDA
SCLK/SCL
L
L
Hi-Z (CSN pin = “H”)
Input
SPI Interface
L
H
Hi-Z (CSN pin = “H”)
function(CSN pin = “L”)
Input
I²C BUS
H
L
“Hi-Z”→ pull-up
“Hi-Z”→ pull-up
H
H
function
function
Note 45. The CSN pin must be set to “H” when not interfacing to a micro controller or the AK7755 is in
power-down mode in SPI interface mode.
■ SPI Interface (I2CSEL pin = “L”)
1. Configuration
The access format is: Command code (8bits) + Address + Data (MSB First).
Bit Length
Command Code 8
MSB bit is R/W flag. The following 7-bits indicate access area such
as PRAM/ CRAM/Registers.
Address
16 or 0
Valid only for those cases where accessed areas have addresses such
as PRAM /CRAM/OFREG. When no address is assigned, there is no
data.
Data
Later Section Write or Read data
SOPCFG bit selects SO output (Hi-z or Low) during CSN = “H”.
Write operation
CSN
SCLK
SI
don’tcare
(L/H)
Command Code (8bit)
SO ^Hi-Z
Low
Address (16bit or 0bit)
Echo Back
Read operation
CSN
Figure 47. SPI Interface Write
Data (write)
X (L/H)
Hi-Z
Low
SCLK
SI
don’tcare
(L/H)
Command Code (8bit)
Address (16bit or 0bit)
SO ^Hi-Z
Low
Echo Back
Figure 48. SPI Interface Read
Data (read)
X (L/H)
Hi-Z
Low
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