UPD784938 Datasheet, PDF (410/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 16 A/D CONVERTER
16.3 A/D Current Cut Select Register (IEAD)
IEAD is a register that selects whether AVDD and AVREF1 are connected.
In a system where AVDD ^.=. AVREF1 and a high accuracy is not required, open the AVREF1 pin. In the normal mode, connect
AVDD and AVREF1. In the standby mode, the connection between these pins is disconnected to lower the power consumption.
IEAD is set with an 8-bit or 1-bit manipulation instruction. RESET input clears IEAD to 00H.
Figure 16-4. A/D Current Cut Select Register (IEAD) Format
Symbol 7
65
4
32
1
0 Address After reset R/W
IEAD 0
00
0
00
0 IEAD0 0FF6CH 00H R/W
IEAD0 Controls Connection between AVDD and AVREF1
0 Disconnects AVDD and AVREF1
1 Connects AVDD and AVREF1
Figure 16-5. A/D Current Cut Select Register Function
AVDD
AVREF1
AVSS
Connection
control
AVDD
Power consumption can be lowered by
controlling connection between AVDD and
AVREF1 with IEAD0.
AVREF1
(open)
AVSS
AVDD ≠ AVREF1 or when high
accuracy is required
AVDD = AVREF1 and when high
accuracy is not required
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Preliminary User’s Manual U13987EJ1V0UM00