AX−SIP−SFEU, AX−SIP−SFEU−API

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14

Table 9. COMMANDS (continued)

Command

Description

Name

AT:Pn=?

Get GPIO Pin Range

Print a list of possible modes for a pin. The table below lists the

response.

Pin

Modes

P0

0, 1, Z, U, A, T

P1

0, 1, Z, U, A

P2

0, 1, Z, U, A

P3

0, 1, Z, U, A

P4

0, 1, Z, U, T

P5

0, 1, Z, U

P6

0, 1, Z, U

P7

0, 1, Z, U

P8

0, 1, Z, U

P9

0, 1, Z, U

P10

0, 1, Z, U

P11

0, 1, Z, U

P12

0, 1, Z, U, A

P13

0, 1, Z, U, A

P14

0, 1, Z, U

AT:Pn=mode

Set GPIO Pin

Set the GPIO pin mode.

For a list of the modes see the command AT:Pn?

AT:ADC Pn[−Pn[ (1V|10V)]]?

Get GPIO Pin Analog Voltage

Measure the voltage applied to a GPIO pin. The command also allows

measurement of the voltage difference across two GPIO pins. In

differential mode, the full scale range may also be specified as 1 V or

10 V. Note however that the pin input voltages must not exceed the

range 0…VDD_IO. The command returns the result as fraction of the

full scale range (1 V if none is specified). The GPIO pins referenced

should be initialized to analog mode before issuing this command.

AT:SPI[(A|B|C|D)]=bytes

SPI Transaction

This command clocks out bytes on the SPI port. The clock frequency is

312.5 kHz. The command returns the bytes read on MISO during output.

Optionally the clocking mode may be specified (default is A):

Mode

Clock Inversion

Clock Phase

A

normal

normal

B

normal

alternate

C

inverted

normal

D

inverted

alternate

D7

D7

D6

D6

D5

D5

D4

D4

D3

D3

D2

D2

D1

D1

D0

D0

SEL(GPIOx)

MOSI

MISO

SCK

A

B

C

D

Note that SEL, if needed, is not generated by this command, and must

instead be driven using standard GPIO commands (AT:Pn=0|1).

AT:CLK=freq,reffreq

Set Clock Generator

Output a square wave on the pin(s) set to T mode. The frequency of

the square wave is (freq / 216) × reffreq. Possible values for reffreq are

20000000, 10000000, 5000000, 2500000, 1250000, 625000, 312500,

156250. Possible values for freq are 0…65535.

AT:CLK=OFF

Turn off Clock Generator

Switch off the clock generator

AT:CLK?

Get Clock Generator

Return the settings of the clock generator. Two numbers are returned,

freq and reffreq.

AT:DAC=value

Set SD DAC

Output a SD DAC value on the pin(s) set to T mode. Parameter value

may be in the range −32768…32767. The average output voltage is

(1/2 + value / 217) × VDD.

An external low pass filter is needed to get smooth output voltages.

The modulation frequency is 20 MHz. A possible low pass filter choice

is a simple RC low pass filter with R = 10 kW and C = 1 mF.