topic Re: How to use Flexbus burst mode in Kinetis Microcontrollers

How to use Flexbus burst mode

hengwu — Thu, 15 Dec 2016 09:14:28 GMT

I want to know the way of flexbus burst mode.

non-burst mode is like this:

*(uint16_t*)ADDR=wdata0;//uint16_t wdata,rdata
rdata0=0;
rdata0=*(uint16_t*)ADDR;

I just want to know how to do to realize the burst mode.

for example,32bit data write to 16 bit data lane or read operation.

Thank you a lot

Re: How to use Flexbus burst mode

xiangjun_rong — Mon, 19 Dec 2016 07:33:00 GMT

Hi, Heng

I think you can use either half-word(16 bits) or word(32 bits) to access the memory no matter whether you use Byte/half-word/word data memory. If you use word to write/read memory and the external memory is half-word memory, the FlexBus is smart enough to generate twice addressing to access the half-word memory.

Hope it can help you

XiangJun Rong

Re: How to use Flexbus burst mode

hengwu — Tue, 20 Dec 2016 03:01:19 GMT

Thank you for your reply.

Actually,my slave device is a FPGA.

I write a 32bite (word) to FPGA via 16 portzise(FB_AD0~FB_AD15).Unfortunatelly,the FB_TBST signal keeps high which should be low when in a burst mode.

Then I make a change that i just write a 32bite (word) to FPGA via 8 portzise(FB_AD0~FB_A7). The FB_TBST signal changes between low and high as the reference diagram shows.I think it is right.

Why can not success via 16 portsize in the same way?

Hope your earliest reply.

Heng Wu