A-D Control Register 1 - Renesas 7700 FAMILY User Manual

A-D CONVERTER
8.2 Block description
8.2.1 A-D control register 0
Figure 8.2.2 shows the structure of the A-D control register 0. The A-D operation mode select bits 0 select
the operation mode of the A-D converter. The other bits are described below.
b7 b6 b5 b4 b3 b2 b1
Fig. 8.2.2 Structure of A-D control register 0
(1) Analog input select bits (bits 2 to 0)
These bits are used to select an analog input pin in the one-shot mode and repeat mode. Pins which
are not selected as analog input pins function as programmable I/O ports.
These bits must be set again when the user switches the A-D operation mode to the one-shot mode
or repeat mode after performing the operation in the single sweep mode, repeat sweep mode 0 or
repeat sweep mode 1.
8–4
b0
A-D control register 0 (Address 1E
Bit Bit name
Analog input select bits
0
(Valid in one-shot and repeat
modes) (Note 1)
1
2
A-D operation mode select bits 0
3
4
Trigger select bit
5
6 A-D conversion start bit
A-D conversion frequency
7
φ
( ) select bit 0
AD
Notes 1: These bits are ignored in the single sweep and repeat sweep mode 0 and repeat
sweep mode 1. (They may be either "0" or "1.")
2: When selecting an external trigger, the AN
3: Use the A-D operation mode select bit 1 (bit 2 at address 1F
repeat sweep mode 0 or repeat sweep mode 1.
4: Writing to each bit (except bit 6) of the A-D control register 0 must be performed while
the A-D converter halts.
7751 Group User's Manual
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16
Functions
b2 b1 b0
0 0 0 : AN selected
0
0 0 1 : AN selected
1
0 1 0 : AN selected
2
0 1 1 : AN selected
3
1 0 0 : AN selected
4
1 0 1 : AN selected
5
1 1 0 : AN selected
6
1 1 1 : AN selected (Note 2)
7
b4 b3
0 0 : One-shot mode
0 1 : Repeat mode
1 0 : Single sweep mode
1 1 : Repeat sweep mode 0 /
Repeat sweep mode 1 (Note 3)
0 : Internal trigger
1 : External trigger
0 : Stop A-D conversion
1 : Start A-D conversion
Refer to Table 8.2.1
pin cannot be used as an analog input pin.
7
RW
At reset
RW
Undefined
RW
Undefined
RW
Undefined
0
RW
0
RW
0 RW
0
RW
0 RW
) to select either the
16