avalon_interface

Sorry for creating confusion with out giving complete info... FPGA Flow can be seen in the block diagram as

TLS Shelf Controller

| i2c | spi

| |

NIOS PIO SPI_INTERFACE ---- DPRAM

___|________|______________|____________|___________

Tri-State_Bridge (Avalon Switch)

________________________________________________

|

|

Flash Slave Interface

TLS: Tunable Laser Source

DPRAM: Internal Dual-Port Ram

SPI_INTERFACE Block is the bridge between processor (on spi interface) and NIOS Core. SPI_INTERFACE looks into present spi-cmd and generates 32bit encoded data and interrupt to NIOS. ISR in NIOS decodes 32bit Code and performs corresponding operation (By generating i2c signals). Central processor operation can be to update 8-bit normal fpga registers or 32bit TLS registers. Since SPI interface is expecting only one clock cycle delay between read cmd and read data.. replica's of normal register and tls registers are managed in dpram and one 32bit array in NIOS.

So SPI_INTERFACE module requires 32bit data from NIOS and 8bit data from DPRAM. Since SPI_INTERFACE is a component of SOPC system, all i/o ports interface has to declared defined. Since 32bit data is expected from avalon-bus, that port signal type has to be writedata..

I am not very clear on data from DPRAM.. Since DPRAM is also another component of SOPC system.. Should i expect DPRAM data from avalon-bus only?, in that case signal-type has to be 'writedata' and 2nd writedata port is not supported by SOPC builder. Or its signal type can be export only..? In that case how to make connection between read-data from dpram module and dpram-rddata of spi_interface. Do we have instantiate DPRAM block again in top-level fpga module? Since it is a part of SOPC system.. It is already present in nios system we are adding in top-level file. I can put my question as

"How to manage data interface between 2 SOPC components??????"

Hope i am a bit clear on FPGA Flow. Actually i am a bit feared that you may not read this post just by looking at the size. Thanks for your patiency to through this.

Block-diagram view is nice in reply window..

Thanks & Regards,

Siva