Kinetis Microcontrollers中的主题 Re: K60 RTS/CTS lines and MQX not working?

K60 RTS/CTS lines and MQX not working?

jpa — Tue, 20 Sep 2011 02:31:45 GMT

Any secrets to getting HW handshaking working on the K60N512 and MQX?

What I have:

* A jumper on J13 7-8 on the TWR-SER board

* A jumper on J18 1-2 on the TWR-SER board

* The other standard jumpers for the K60 demos

* I open the port using fopen(devname, (char const *) IO_SERIAL_HW_FLOW_CONTROL);

* For kicks, I poll the hardware line using ioctl(dev, IO_IOCTL_SERIAL_GET_HW_SIGNAL, &signals) and test for IO_SERIAL_CTS and IO_SERIAL_RTS and the result of the test doesn't change, even though I can see the signal changing with a breakout box.

* serial port is configured using the interrupt driver

Transmissions from the K60 board continue no matter the state of the external pins...which I guess makes sense if MQX can't see the proper state of the pins either.

JPA

Re: K60 RTS/CTS lines and MQX not working?

jpa — Tue, 20 Sep 2011 04:06:06 GMT

Well, I thought I had it by defining

BSPCFG_ENABLE_TTYD_HW_SIGNALS

in the user_config.h file, but after rebuilding the BSP and PSP, it's still no go. (or rather, still no 'stop')

JPA

Re: K60 RTS/CTS lines and MQX not working?

Dekiru — Sun, 25 Sep 2011 09:45:27 GMT

Hi,

Can you change to using pooling in stead of interrupt?

Look at the MQX code, you can see that they limited hardware hanshaking for polling only intentionally.

Regards

Re: K60 RTS/CTS lines and MQX not working?

jpa — Wed, 28 Sep 2011 00:04:17 GMT

Thanks for the suggestion, I'll give it a try.

I wonder why that is, though? Does it say why in the code? Handshaking is built into the hardware, so I wouldn't have thought it would complicate the interrupt handling.

I'm new to MQX so I may be missing something, but polling seems antithetical to a multi-tasking RTOS.

JPA