ASAHI KASEI

[AK4342]

MS0506-E-02

2006/07

- 29 -

Serial Control Interface

1. 3-wire Serial Control Mode (I2C pin = “L”)

Internal registers may be written by using the 3-wire µP interface pins (CSN, CCLK and CDTI). The data on this interface

consists of a 2-bit Chip address (Fixed to “01”), Read/Write (Fixed to “1”), Register address (MSB first, 5bits) and

Control data (MSB first, 8bits). Each bit is clocked in on the rising edge (“

↑”) of CCLK. Address and data are latched on

the CSN falling edge (“

↓”). Clock speed of CCLK is 5MHz (max). The value of internal registers are initialized by PDN

pin = “L”.

CDTI

CCLK

CSN

C1

0

12

3

4

5

6

7

8

9

10

11

12

13

14

15

D4

D5

D6

D7

A1

A2

A3

A4

R/W

C0

A0

D0

D1

D2

D3

C1-C0:

Chip Address (Fixed to “01”)

R/W:

READ/WRITE (Fixed to “1”, Write only)

A4-A0:

Register Address

D7-D0:

Control Data

Figure 21. Serial Control I/F Timing