October 2012
SNLU120
5
2.7. For SMBUS mode control of the EQ, VOD and De-emphasis level:
Set ENSMB = 1 (1kohm to VIH) by using the SW2 (3-2-1) = (OFF-OFF-
ON)
.
Set SW4 pin1,2 to the ON position so the SMBUS signals are connected.
Set SW3 pin1 thru pin6 switches to the OFF position so they do not connect to the SDA and SCL line.
Set the SW1 and SW5 for the AD[3:0] pins. AD[3:0]=0000 sets device slave address = B0’hex.
Connect SDA, SCL and GND to J25. Please refer to datasheet for register map for EQ, VOD and DEM.
Examples of register writes to configure the device:
0x06 0x18; disable CRC to allow control of register for EQ, VOD and DEM
0x0f 0x15; set EQ for S_INA0
0x16 0x15; set EQ for S_INB0
0x17 0xac; set D_OUT0 VOD to 1.0V
0x18 0x00; set D_OUT0 DEM to 0 dB
0x1d 0x15; set EQ for S_INA1
0x24 0x15; set EQ for S_INB1
0x25 0xac; set D_OUT1 VOD to 1.0V
0x26 0x00; set D_OUT1 DEM to 0 dB
0x2c 0x15; set EQ for D_IN0
0x2d 0xac; set S_OUTA0 VOD to 1.0V
0x2e 0x04; set S_OUTA0 DEM to -6dB
0x34 0xac; set S_OUTB0 VOD to 1.0V
0x35 0x04; set S_OUTB0 DEM to -6dB
0x3a 0x15; set EQ for D_IN1
0x3b 0xac; set S_OUTA1 VOD to 1.0V
0x3c 0x04; set S_OUTA1 DEM to -6dB
0x42 0xac; set S_OUTB1 VOD to 1.0V
0x43 0x04; set S_OUTB1 DEM to -6dB
0x5e 0x07; override SEL1, SEL0 and INPUT_EN pin and use Reg_0x5f
0x5f 0xf0; set SEL1, SEL0 to select input A and output A, 1:2 fan-out is disabled, so B outputs are disabled.