Using the Memory Controller Interface
Memory Controller Interface functionality
- Each of the Convey application engines are connected to 8 MCs (Memory Controllers) through 300MHz DDR interface.
- Each of the 8 MC interfaces consists of two 150MHz ports (odd port and even port). So, the MC interface contains a total of 16 port.
- The data from the two even and odd ports are multiplexed onto the same 300 MHz channel in the MC interface.
- Each of the even and odd ports has its request signals and response signals.
- Refer to section 188.8.131.52 in the PDK reference manual for further information.
Memory Controller Interface Signals
The 4th MC interface of the 8 MC interfaces has the signals shown in the table below. There exist MC interfaces for n = 0 to 7. Also, you can notice that the signals are the same for the even and odd port. However, the signals for the even port use the suffix
_e and the signals for the odd port use the suffix
|Even Port||Odd Port|
Reading from Memory
- Before requesting any read from the memory, you have to make sure that
mci_rd_rq_stall_* = '0', where
iis the MC interface port number (could be from 0 to 7).
- To request a read from memory, you have to assert the signal
mci_req_ld_*and put the address of the data you want to read on the port
mci_req_size_*<1:0>is used to indicate if you want to read a byte, word, double-word or quad-word (i.e. 0x0 for byte, and 0x3 for quad-word).
- You can get requested data from the
mci_rsp_data_*<63:0>bus when the signal
- The lower 32 bits of
mci_req_wrd_rdctl_*<63:0>will be returned as
mci_rsp_rdctl_o<31:0>. You should set it while requesting a read and check it in the response to identify your request.
Writing to Memory
- Before requesting any write to the memory, you have to make sure that
mci_wr_rq_stall_* = '0'.
- To request a write to memory, you have to assert the signal
mci_req_st_*and put the address of the data you want to write to on the port
mci_req_size_*<1:0>is used to indicate the size as in the read scenario above.
- The data you want to write should goes on
- Convey PDK Reference Manual (.pdf) - Sections 9.3.3