YMF795
-21-
■
Power-down control division diagram
Power-down of the LSI can be controlled for each divided internal function.
The power-down is controlled by Index 38h.
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Explanation of each bit
DP0
This is the bit to power off the whole digital section.
Consumption current of the digital part can be minimized because internal clock stops.
Contents of the registers are held but data in the FIFO are cleared.
AP1
This is the bit to power off the VREF circuit.
If AP1 is set to “1”, the whole analog section stops. Because an analog center voltage is made by VREF circuit.
AP2
This is the bit to power off the FM volume section, EQ circuit, speaker volume, and non-inverted amplifier side of
speaker output section.
SYNC
SDIN
SCLK
/RST
/IRQ
EQ1
VREF
Serial
I/F
DVDD
D
V
SS
VOL
32-step
P
ower
down
Con
trol
Register
RAM
FM
Synthesizer
Simultaneous
Sound
Generation
4-tone
DAC
AMP
AVDD
A
V
SS
Timing Generator
HP
OUT
VOL
32-step
FIFO
16b
×
32w
EQ
EQ2
EQ3
SPOUT1
VREF
Controlled by
using DP bit
Controlled by
using AP4 bit
Controlled by
using AP3 bit
Controlled by
using AP1 bit
Controlled by
using AP2 bit
VOL
32-step
CLK_I
SPVSS
SPOUT2
Содержание YMF795
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