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CHAPTER 12 A/D CONVERTER
Table 12.4-2 Explanation of Functions of Each Bit in A/D Control Register 2 (ADC2)
Bit name Function
bit7 Unused bit • The value during read is not determined.
• Write does not affect operations.
bit6,
bit5 RESV4,RESV3:
Reserved bits • This bit is a reserved bit.
• Be sure to write 00B to these bits.
bit4 ADCK:
Selecting an input
clock bit
This bit is used to select an input clock for activation of A/D conversion
functions in the state where continuous activation is performed (EXT = 1).
When this bit is "0", the internal clock with an oscillation frequency (selected
using the output of a time-base timer) divided by 28 is selected. When "1", the
output of an 8/16-bit capture timer/counter (TO: 16-bit mode) is selected.
bit3 ADIE:
Enabling an interrupt
request bit
This bit is used to enable and disable the output of an interrupt to the CPU.
When this bit and the interrupt request flag bit (ADC1: ADI) are "1", an
interrupt request is output.
bit2 RESV2:
Reserved bit • This bit is a reserved bit.
• Be sure to write "0" to this bit.
bit1 EXT:
Bit for enabling
continuous activation
This bit is used to select whether the A/D conversion functions are to be
activated with software or activated continuously in synchronization with an
input clock.
When this bit is "0", software activation with the bit for activating A/D
conversion (ADC1: AD) is enabled. When "1", continuous activation on the
rising edge of the clock selected using the bit for selecting an input clock
(ADC2: ADCK) is enabled.
bit0 RESV1:
Reserved bit • This bit is a reserved bit.
• Be sure to write "1" to this bit.