setting an RX and TX channels on the same DMA

[Altera_Forum]

Hi 

 In my current system there are 2 DMAs for transferring data between a peripheral and an SRAM. one DMA is dedicated for RX and the other is for RX. for a better resource usage I'm trying to merge the 2 DMAs into one, the idea is to define 2 DMA channels to get the same functionality with half the resource. for some reason I fail to define that in software. I'm using Q12.0 sp2 with SOPC builder, and a NIOS processor. the software uses the uCOS II operating system and I'm using the HAL functions.  can any one point me to a reference design a tutorial on how to achieve my goal?

[Altera_Forum]

Some more info: 

I forgot to add that both the peripheral and the SRAM are MM avalon.   Today I found out that if I run my software on a DMA that has it's read master connected to SRAM and write master connected to the peripheral the DMA works. when I connect the both the read and write masters to the SRAM the DMA (configured by the same software) stops to work.