
[AK4671]
MS0666-E-00
2007/10
- 114 -
■
Serial Control Interface
(1) 4-wire Serial Control Mode (I2C pin = “L”)
Internal registers may be written by using the 4-wire μP interface pins (CSN, CCLK, CDTI and CDTO).
In case except for 10bit SAR ADC data read, the data on this interface consists of a 3-bit Chip address (fixed to “100”),
Read/Write (1bit), Register address (MSB first, 7bits) and Control data (MSB first, 8bits).
In case of 10bit SAR ADC data read, the data on this interface consists of a 3-bit Chip address (fixed to “101”),
Read/Write (1bit: fixed to “0”) and SAR ADC Data (MSB first, 10bits).
Address and data is clocked in on the rising edge of CCLK and data is clocked out on the falling edge. Address and data
are latched on the 24th CCLK rising edge (“
↑
”) after CSN falling edge (“
↓
”) for write operations and CDTO bit goes to
Hi-Z after CSN rising edge (“
↑
”). CSN should be set to “H” once after 24th CCLK for each address. The clock speed of
CCLK is 5MHz (max). The value of internal registers is initialized at PDN pin = “L”.
CSN
CDTI
CCLK
C2
0
1
2
3
4
5
6
7
16
17
18
19 20
21
22
23
D4
D5
D6
D7
0
0
0
C0
R/W
C1
0
D0
D1
D2
D3
CDTO
Hi-Z
WRITE
CDTI
C2
D4
D5
D6
D7
0
0
0
C0
R/W
C1
0
D0
D1
D2
D3
CDTO
Hi-Z
READ
(except for
10bit SAR ADC Data)
D4
D5
D6
D7
D0
D1
D2
D3
Hi-Z
0
8
9
10
11
12
13
14
15
A1
A2
A3
A4
A5
A6
A0
0
A1
A2
A3
A4
A5
A6
A0
Clock,
"H" or "L"
Clock,
"H" or "L"
"H" or "L"
"H" or "L"
"H" or "L"
"H" or "L"
C2-C0: Chip Address (Fixed to “100”)
R/W: READ/WRITE (0: READ, 1: WRITE)
A6-A0: Register Address
D7-D0: Control Data
Figure 96. Serial Control I/F Timing (Except for 10bit SAR ADC Data)
CCLK
CSN
0
1
2
3
4
5
6
7
16
17 18 19 20 21 22
23
8
9
10
11
12
13
14
15
CDTI
C2
D4
D5
D6
D7
0
0
0
C0
R/W
C1
0
D0
D1
D2
D3
CDTO
Hi-Z
READ
(10bit SAR ADC Data)
0
0
D0
D1
0
0
0
0
Hi-Z
D6
D7
D8
D9
D2
D3
D4
D5
Clock,
"H" or "L"
"H" or "L"
Clock,
"H" or "L"
"H" or "L"
C2-C0: Chip Address (Fixed to “101”)
R/W: READ/WRITE (Fixed to “0”: READ Only)
D9-D0: SAR ADC Data
Figure 97. Serial Control I/F Timing (10bit SAR ADC Data)