7480 datasheet(162/337 Pages) RENESAS

162 / 337 page

7480 Group and 7481 Group User's Manual

1-145

HARDWARE

Figure 1.15.5 Change of A-D Conversion Register and Comparison Voltage during A-D Conversion

A-D conversion interrupt

When A-D conversion is completed, the A-D conversion completion interrupt request bit of interrupt request

Reads from A-D conversion register

When A-D conversion is completed, the A-D conversion register is read to obtain the A-D conversion result.

The completion of A-D conversion can be acknowledged by any of the following conditions:

• The A-D conversion completion bit is ‘1’.

• The A-D conversion completion interrupt request bit is ‘1’.

• The branch to A-D conversion completion interrupt service routine occurs (when A-D conversion completion

interrupt enabled).

Note: Do not read from the A-D conversion register during A-D conversion operation.

A-D conversion time

A-D conversion ends in 50 cycles after its start. Because the A-D converter uses the clock input divided

by 2, f(XIN)/2, as the operating clock, A-D conversion time is fundamentally obtained by the following

formula:

A-D conversion time =

× conversion cycles (50 cycles)

(12.5

µs at f(XIN) = 8 MHz)

1.15 A-D Converter

1 0000 0 0 0

10 0 0 0 0

1 000 0 0 0

12 3 4 5 6 7

VREF

512

VREF

512

VREF

512

00 0 0 0 0 0 0

12 3 45 6 7 8

VREF

512

VREF

256

.......

.....

The contents of A-D conversion register

At A-D conversion start

At the first comparison start

At the second comparison start

At the third comparison start

At the eighth comparison start

At A-D conversion completed

(at the eighth conversion completed)

The digital value corresponding to

analog input voltage

: The determined value obtained by the m-th (m=1 to 8) comparison result

Comparison voltage (Vref) [V]

–

f(XIN)

7480 Datasheet(PDF) 162 Page - Renesas Technology Corp

7480 Datasheet(HTML) 162 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL