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GPIO Capability

G.2 GPIO Capability

The USB-MODEVM has seven GPIO lines. Access them by specifying the interface to be 0x08, and then using the standard format for packets—but addresses are unnecessary. The GPIO lines are mapped into one byte (see Table G-3):

Table G-3. GPIO Pin Assignments

Bit 7

6

5

4

3

2

1

0

x

P3.5

P3.4

P3.3

P1.3

P1.2

P1.1

P1.0

Example: write P3.5 to a 1, set all others to 0:

[0]0x18 --> write, GPIO

[1]0x00 --> this value is ignored

[2]0x01 --> length - ALWAYS a 1

[3]0x00 --> this value is ignored

[4]0x40 --> 01000000

The user may also read back from the GPIO to see the state of the pins. Let's say we just wrote the previous example to the port pins.

Example: read the GPIO

[0]0x08 --> read, GPIO

[1]0x00 --> this value is ignored

[2]0x01 --> length - ALWAYS a 1

[3]0x00 --> this value is ignored

The return packet should be:

[0]0x28

[1]0x00

[2]0x01

[3]0x00

[4]0x40

SLAU261–November 2008

USB-MODEVM Protocol

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Texas Instruments TLV320AIC3107EVM-K quick start Gpio Capability, Table G-3. Gpio Pin Assignments