Multi-SPI

Haiyu Zhang

When DSP 28035 is used as master to communicate with other devices through SPI, I should use SPISTE (GPIO27, GPIO15 or GPIO19) to enbale slave transmit (assuming active low here). Could I use other general purpose I/O except for the three mentioned above to enable the slave transmit? If that doesn't work, how can I enable three SPI communications (three devices) through three transmit enable pins asynchronously?

over 13 years ago

0 Trey German289 over 13 years ago

TI__Mastermind 22025 points

Haiyu,

We provide one hardware chip select line (SPISTEA), but you are certainly able to implement this functionality in software using a GPIO. In fact this is the only way to interface 2 or more SPI devices to the SPI peripheral on C2000 devices.

Regards,

Trey

0 Kris Parrent over 13 years ago

TI__Genius 15260 points

I provide an example here as this gets a bit tricky figuring out when to set your GPIO slave selects high:

http://e2e.ti.com/support/microcontrollers/tms320c2000_32-bit_real-time_mcus/f/171/p/171156/650653.aspx#650653

The other method I did not mention in that thread is to externally connect (the SPI hardware) SPISTE to XINT to generate an interrupt when it returns high. This is the most MIPS conservative method.

Kris

C2000™︎ microcontrollers

C2000 microcontrollers forum

Multi-SPI