How VisSim maps F28335 GPIOs?

Altair Forum User

Submitted by linklessa on Fri, 11/06/2009 - 22:19 

Hi. I'm working with a eZdsp F28335 from TI. I want to simply test a output by a GPIO, but when i configure the digital/analog output, there are no responses. I used the blink283x example, and noted that the output block that controls the LED blinking is configured: Digital, Channel 0, Port B, Bit Width 1, Target Board 0. In the manual, the GPIO pin that controls this same LED is GPIO32!

How can I configure the output blocks (and other necessary configurations) to get a output signal in a GPIO 0, per example?

Altair Forum User

Submitted by Anders89 on Sat, 11/07/2009 - 00:05.

The GPIO access on the F28xx series (and most other targets) is based on register access to a port of contiguous GPIO bits. To map easily onto the hardware, VisSim also provides a port based reference to the GPIO channels. The F28335 port registers are 32 bits long, so GPIO 0 is channel 0, port A. GPIO 31 is channel 31 port A. GPIO 32 is channel 0 port B, GPIO 63 is chan 31 port B, GPIO 64 is chan 0, port C and so on.
VisSim also allows referencing multiple contiguous GPIO lines as a single value. For instance, if you wanted to read 3 Hall sensor lines on GPIO 17-19, you configure the Digital In block as Port A, bit width = 3, offset = 17.