HD404449 Datasheet, PDF (100/125 Pages) Hitachi Semiconductor – HD404449 SERIES

HD404449 Series
Note on Use: Use the SEM and SEMD instructions to write data to the A/D start flag (ADSF: $020, bit 2),
but make sure that the A/D start flag is not written to during A/D conversion. Data read from the A/D data
register (ADRL: $017, ADRU: $018) during A/D conversion cannot be guaranteed.
The A/D converter does not operate in the stop, watch, and subactive modes because of the OSC clock.
During these low-power dissipation modes, current through the resistor ladder is cut off to decrease the
power input.
A/D mode register (AMR: $016)
Bit
Initial value
Read/Write
Bit name
3
0
W
AMR3
2
1
0
0
—
0
W
—
W
AMR2 Not used AMR0
AMR3
0
0
1
1
AMR2
0
1
0
1
Analog input selection
AN₀
AN₁
AN₂
AN₃
AMR0
0
1
Conversion time
34t_cyc
67t_cyc
Figure 82 A/D Mode Register (AMR)
ADRU: $018
3
2
1
0
ADRL: $017
3
2
1
0
MSB
LSB
Bit 7
Bit 0
Figure 83 A/D Data Registers
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