AK7735EQ Datasheet, PDF (67/142 Pages) Asahi Kasei Microsystems – Dual DSP with 4chADC + 4chDAC + 4chSRC

[AK7735]
4. Clock Reset
When CKRESETN bit = “0” after power-down mode is released (PDN pin = “H”), the AK7735 is in clock
reset state. All blocks except the power supply circuits for REF generation and digital circuits are in
power-save mode. Even the internal PLL for master clock generation is powered down.
Control register settings should be made with an interval of 1ms (min) after releasing the power-down
mode. DSP program and coefficient data can be written in 1ms by setting DLRDY bit “0” → “1” during
clock reset. DLRDY bit must be set to “0” after downloading ( Figure 47).
112H
Necessary system clocks (Table 4, Table 5) should be input before the clock reset is released. The
internal PLL starts operation and the master clock is generated when clock reset is released
(CKRESETN bit = “1”). DSP program and coefficient data should be sent 10ms after clock reset release
or after confirming “H” output of PLLLOCK signal from the STO pin (Figure 46).
System clocks must be changed during clock reset or in power-down mode (PDN pin = “L”). The PLL
and the internal clocks are stopped by this clock reset and the clock change can be done safely. Change
register settings and system clock frequencies during the clock reset. After system clock is stabilized, the
PLL starts operation by setting CKRESETN bit to “1”.
Clock operated blocks (ADC, DAC and SRC) must be powered down before executing clock reset.
These blocks can be powered down simultaneously by setting HRESETN bit to “0” from “1”. Set
HRESETN bit to “1” from “0” with an interval of 10ms for stabilization of PLL after clock reset is released.
XTI
BICK1
REFSEL Mode 0
REFSEL Mode 1
CSN
SCLK (Simplified)
SI
C0 00 6E 00
HRESETN
DxRESETN
C0 00 01 00
C0 00 00 xx 8x
C0 00 6E 0F
CKRESETN
10ms
Blocks except PLL are
PLL Stop
PLL Stabilize
stopped
Input clock and clock mode can be changed
Command Code
& DSP Program Transition
Figure 48. Clock Mode Switching Sequence
Resume
Operation
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2016/12