SM6452AM/BM

NIPPON PRECISION CIRCUITS—11

SM6452BM

Transfer format

SM6452BM. The transfer format is shown in figure 2.

As shown in figure 2, the data format comprises 3 bytes. After the SM6452BM receives 8 bits for each byte, an

acknowledge signal (ACK) on SDA goes LOW to confirm the data transfer.

Data format

s

Byte 1 (slave address)

The first byte is slave address. The SM6452BM address (AD6 to AD0) is 1000000. The 8th bit indicates

information write and should be set LOW.

s

Bytes 2 and 3

Bytes 2 and 3 are the channel select and gain/attenuation level set bits. Byte 2 represents data bits D15 to D8,

and byte 3 represents data bits D7 to D0.

Data description (D15 to D0)

s

D15, D14

Don’t care.

s

D13 to D8

Chip address bits. Each of 6 channels is set when the corresponding bit is set HIGH.

• D13: channel 1

• D12: channel 2

• D11: channel 3

• D10: channel 4

• D9: channel 5

• D8: channel 6

s

D7 to D0

Gain/attenuation set bits. The gain/attenuation setting for ATT register settings are shown in table 1.

Figure 2. Microcontroller input data timing

SDA

SCL

AD6

L

ACK

AD0

D15

D8

D7

D0

ACK

ACK

Start condition

Stop condition

First Byte

(Slave address)

Second Byte

Third Byte

AD6 to AD0 = 1000000