FUJITSU F2MCTM-16LX User Manual

Page 370

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CHAPTER 18 8-/10-BIT A/D CONVERTER

Note:

Do not set the A/D conversion mode set bits (MD1 and MD0) and A/D conversion end channel select bits
(ANE3, ANE2, ANE1 and ANE0) through read-modify-write commands after the start channel is set in
the A/D conversion start channel select bits (ANS3, ANS2, ANS1 and ANS0).
The ANS3, ANS2, ANS1 and ANS0 bits will read the last conversion channel until the A/D conversion
operation starts. Accordingly when the MD1 and MD0 bits and the ANE3, ANE2, ANE1 and ANE0 bits
are set through read-modify-write commands after the start channel is set in the ANS3, ANS2, ANS1 and
ANS0 bits, the values of the ANE3, ANE2, ANE1 and ANE0 bits may be rewritten.

Setting of Sampling Time (ST2 to ST0 bits)

bit3
to
bit0

ANE3 to ANE0:
A/D conversion end
channel select bits

These bits set the channel at which A/D conversion terminated.
Start channel < end channel:
A/D conversion starts at channel set by A/D conversion start channel
select bits (ANS3 to ANS0) and terminates channel set by A/D
conversion end channel select bits (ANE3 to ANE0)
Start channel = end channel:
A/D conversion is performed only for one channel set by A/D
converter start (= end) channel select bits (ANE3 to ANE0 = ANS3 to
ANS0).
Start channel > end channel:
Do not set.
Continuous conversion mode and pause-conversion mode:
When A/D conversion terminated at the channel set by the A/D
conversion end channel select bits (ANE3 to ANE0), it returns to the
channel set by the A/D conversion start channel select bits (ANS3 to
ANS0).
Note:
Do not set the A/D conversion end channel select bits (ANE3 to
ANE0) during A/D conversion.

Table 18.3-5 Function of A/D Setting Register (ADSR0/ADSR1) (2/2)

Bit Name

Function

Table 18.3-6 Relation between ST2 to ST0 Bits and Sampling Time

ST2

ST1 ST0 Setting

of

Sampling

Time

Setting example (

φ

: Internal

operating frequency)

0

0

0

4 machine cycles

φ= 8 MHz: 0.5 µs

0

0

1

6 machine cycles

φ= 8 MHz: 0.75 µs

0

1

0

8 machine cycles

φ= 16 MHz: 0.5 µs

0

1

1

12 machine cycles

φ= 24 MHz: 0.5 µs

1

0

0

24 machine cycles

φ= 8 MHz: 3 µs

1

0

1

36 machine cycles

φ= 16 MHz: 2.25 µs

1

1

0

48 machine cycles

φ= 16 MHz: 3.0 µs

1

1

1

128 machine cycles

φ= 24 MHz: 5.3 µs

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