
ASAHI KASEI
[AK4181A]
MS0313-E-00
2004/06
14
XP
PENIRQN
Driver ON
YN
100k
EN2
50k
Driver OFF
EN1
Figure 7 PENIRQ Functional Block Diagram
BUSY
DOUT
S
A2
A0
A1
MO
PD1
PD0
SER/
DFR
DCLK
DIN
11
9
8
7
6
5
4
3
2
1
0
10
CSN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
CONV
Internal
AXIS = ((!A2) & (!A1) & (A0))
/* X-axis Measurement */
| ((!A2) & (A1) & (A0))
/* Z1 Measurement */
| ((A2) & (!A1) & (!A0))
/* Z2 Measurement */
| ((A2) & (!A1) & (A0));
/* Y-axis Measurement */
EN1 = ((!CSN) & (!CONV) & AXIS & PD0)
/* CSN=”L”, X/Y/Z1/Z2 Measurement, PD0 = 1, NOT “CONV period” */
| ((!CSN) & AXIS & CONV);
/* CSN=”L”, X/Y/Z1/Z2 Measurement, “CONV period” */
EN2 = ((!CSN) & (!CONV) & (!PD0))
/* CSN=”L”, PD0 = 1, NOT “CONV period” */
| (CSN & (!(PD1& PD0));
/* CSN=”H”, (PD0, PD1) is not (1,1) */
Power on Sequence
On the AK4181A first powers up, the register value including power down mode, internal reference (PD1, PD0) holds unfixed
before sending first control command. On this condition pen interrupt function may be disable, internal reference may also be ON
state ([PD1, PD0] = [1,1]). 8bit control command must be sent as quick as possible when first power up to fix the internal register
value. The sequence is that 1) Power On with CSN = “L” or “H” then CSN = “H”. 2) Send control command after CSN = “L”. 3)
CSN = “H” again. Once sending command to fix the internal register after first power up, the state of AK4181A is held on the
condition of state as last command issued.