[AK4675]
When PLL reference clock input is LRCK or BICK pin, the sampling frequency is selected by FS3-2 bits (Table 6).
Mode
0
1
2
FS3 bit
FS2 bit
FS1 bit
Don’t care
Don’t care
Don’t care
FS0 bit
Don’t care
Don’t care
Don’t care
Sampling Frequency Range
0
0
1
0
1
8kHz ≤ fs ≤ 12kHz
12kHz < fs ≤ 24kHz
24kHz < fs ≤ 48kHz
N/A
Don’t care
(default)
Others
Others
Table 6. Setting of Sampling Frequency at PMPLL bit = “1” (Reference Clock = LRCK or BICK pin)
■ PLL Unlock State
1) PLL Master Mode (PMPLL bit = “1”, M/S bit = “1”)
In this mode, the LRCK and BICK pins go to “L” and irregular frequency clock is output from the MCKO pins at MCKO
bit is “1” before the PLL goes to lock state after PMPLL bit = “0” Æ “1”. If MCKO bit is “0”, the MCKO pin goes to “L”.
(Table 7)
After the PLL is locked, a first period of LRCK and BICK may be invalid clock, but these clocks return to normal state
after a period of 1/fs.
When sampling frequency is changed, the BICK and LRCK pins do not output irregular frequency clocks but go to “L” by
setting PMPLL bit to “0”.
MCKO pin
MCKO bit = “0” MCKO bit = “1”
PLL State
BICK pin
LRCK pin
After that PMPLL bit “0” Æ “1”
PLL Unlock (except above case)
PLL Lock
“L” Output
“L” Output
“L” Output
Invalid
Invalid
See Table 9
“L” Output
Invalid
See Table 10
“L” Output
Invalid
1fs Output
Table 7. Clock Operation at PLL Master Mode (PMPLL bit = “1”, M/S bit = “1”)
2) PLL Slave Mode (PMPLL bit = “1”, M/S bit = “0”)
In this mode, an invalid clock is output from the MCKO pin before the PLL goes to lock state after PMPLL bit = “0” Æ
“1”. After that, the clock selected by Table 9 is output from the MCKO pin when PLL is locked. ADC and DAC output
invalid data when the PLL is unlocked. For DAC, the output signal should be muted by writing “0” to DACL, DACR,
DACH and DACS bits.
MCKO pin
PLL State
MCKO bit = “0” MCKO bit = “1”
After that PMPLL bit “0” Æ “1”
PLL Unlock
PLL Lock
“L” Output
“L” Output
“L” Output
Invalid
Invalid
Output
Table 8. Clock Operation at PLL Slave Mode (PMPLL bit = “0”, M/S bit = “0”)
MS0963-E-00
2008/05
- 53 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
