÷N
BCLK
DAC_CLK
DIG_MIC_CLK
DAC_MOD_CLK
ADC_CLK
BDIV_CLKIN
N = 1,2,...,127,128
Clock Generation and PLL
Table 2-20. CODEC CLKIN Clock Dividers
Divider
Bits
NDAC
Page 0, Register 11, D(6:0)
MDAC
Page 0, Register 12, D(6:0)
DOSR
Page 0, Register 13, D(1:0) + Page 0, Register 14, D(7:0)
NADC
Page 0, Register 18, D(6:0)
MADC
Page 0, Register 19, D(6:0)
AOSR
Page 0, Register 20, D(7:0)
The DAC Modulator is clocked by DAC_MOD_CLK. For proper power-up of the DAC Channel, these
clocks must be enabled by configuring the NDAC and MDAC clock dividers ( Page 0,Register 11, D(7) =1
and Page 0, Register 12, D(7)=1). When the DAC channel is powered down, the device internally initiates
a power-down sequence for proper shut-down. During this shut-down sequence, the NDAC and MDAC
dividers must not be powered down, or else a proper low power shut-down may not take place. The user
can read the power-status flag in Page 0, Register 37, D(7) and Page 0, Register 37, D(3). When both
flags indicate power-down, the MDAC divider may be powered down, followed by the NDAC divider.
The is clocked by DIG_MIC_CLK. For proper power-up of the ADC Channel, these clocks are enabled by
the NADC and MADC clock dividers (Page 0,Register 18, D(7) =1 and Page 0, Register 19, D(7)=1).
When the ADC channel is powered down, the device internally initiates a power-down sequence for
proper shut-down. During this shut-down sequence, the NADC and MADC dividers must not be powered
down, or else a proper low power shut-down may not take place. The user can read the power-status flag
in Page 0, Register 36, D(6) and Page 0, Register 36, D(2). When both flags indicate power-down, the
MADC divider may be powered down, followed by NADC divider.
When ADC_CLK is derived from the NDAC divider output, the NDAC must be kept powered up till the
power-down status flags for ADC do not indicate power-down. When the input to the AOSR clock divider
is derived from DAC_MOD_CLK, then MDAC must be powered up when ADC_FS is needed ( i.e. when
WCLK is generated by TLV320DAC3203) and can be powered down only after the ADC power-down flags
indicate power-down status.
In general, all the root clock dividers should be powered down only after the child clock dividers have been
powered down for proper operation.
The TLV320DAC3203 also has options for routing some of the internal clocks to the output pins of the
device to be used as general purpose clocks in the system. The feature is shown in
.
Figure 2-46. BCLK Output Options
63
SLAU434 – May 2012
TLV320DAC3203 Application
Copyright © 2012, Texas Instruments Incorporated