AD6688 datasheet(50/138 Pages) AD

50 / 138 page

AD6688

Data Sheet

Rev. 0 | Page 50 of 138

GPIO Level Control Mode

The GPIO pins determine the exact NCO channel selected.

The following procedure must be followed to use GPIO level

control for NCO channel selection:

1. Configure one or more GPIO pins as NCO channel

selection inputs. GPIO pins not configured as NCO

channel selection are internally tied low.

a. To use GPIO_A0, write Bits[2:0] in Register 0x0040 to

0x6 and Bits[3:0] in Register 0x0041 to 0x0.

b. To use GPIO_B0, write Bits[5:3] in Register 0x0040 to

0x6 and Bits[7:4] in Register 0x0041 to 0x0.

c. To use GPIO_A1, write Bits[3:0] in Register 0x0042 to

0x0.

d. To use GPIO_B1, write Bits[7:4] in Register 0x0042 to

0x0.

2. Configure the NCO channel selector in GPIO level control

mode by setting Bits[7:4] in the NCO control registers

(Register 0x0314, Register 0x0334, Register 0x0354, and

desired GPIO pin ordering.

3. Select the desired NCO channel through the GPIO pins.

GPIO Edge Control Mode

Low to high transition on a single GPIO pin determines the

exact NCO channel selected. The internal channel selection

counter is reset by either SYSREF± or the DDC soft reset.

The following procedure must be followed to use GPIO edge

control for NCO channel selection:

1. Configure one or more GPIO pins as NCO channel

selection inputs.

a. To use GPIO_A0, write Bits[2:0] in Register 0x0040 to

0x6 and Bits[3:0] in Register 0x0041 to 0x0.

b. To use GPIO_B0, write Bits[5:3] in Register 0x0040 to

0x6 and Bits[7:4] in Register 0x0041 to 0x0.

c. To use GPIO_A1, write Bits[3:0] in Register 0x0042 to

0x0.

d. To use GPIO_B1, write Bits[7:4] in Register 0x0042 to

0x0.

2. Configure the NCO channel selector in GPIO edge control

mode by setting Bits[7:4] in the NCO control registers

(Register 0x0314, Register 0x0334, Register 0x0354, and

desired GPIO Pin.

3. Configure the wrap point for the NCO channel selection

by setting Bits[3:0] in the NCO control registers

(Register 0x0314, Register 0x0334, Register 0x0354, and

to wrap at Channel 4 (0, 1, 2, 3, 4, 0, 1, 2, 3, 4, and so on).

4. Transition the selected GPIO pin from low to high to

increment the NCO channel selection.

NCO channel selection is controlled directly through the

AD6688 Folha de dados(PDF) 50 Page - Analog Devices

AD6688 Folha de dados(HTML) 50 Page - Analog Devices

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

Folha de dados Download

Ligação URL