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 9.3.3.1 in the PDK for further informations.
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 _o
| Even Port | Odd Port |
|---|---|
| mc4_req_ld_e | mc4_req_ld_o |
| mc4_req_st_e | mc4_req_st_o |
| mc4_req_size_e<1:0> | mc4_req_size_o<1:0> |
| mc4_req_vadr_e<47:0> | mc4_req_vadr_o<47:0> |
| mc4_req_wrd_rdctl_e<63:0> | mc4_req_wrd_rdctl_o<63:0> |
| mc4_req_flush_e | mc4_req_flush_o |
| mc4_rd_rq_stall_e | mc4_rd_rq_stall_o |
| mc4_wr_rq_stall_e | mc4_wr_rq_stall_o |
| mc4_rsp_push_e | mc4_rsp_push_o |
| mc4_rsp_stall_e | mc4_rsp_stall_o |
| mc4_rsp_data_e<63:0> | mc4_rsp_data_o<63:0> |
| mc4_rsp_rdctl_e<31:0> | mc4_rsp_rdctl_o<31:0> |
| mc4_rsp_flush_cmplt_e | mc4_rsp_flush_cmplt_o |
Reading from Memory
Before requesting any read from the memory, you have to make sure that mci_rd_rq_stall_x = '0'. To request a read from memory, you have to assert the signal mci_req_ld_x and put the address of the data you want to read on the port mci_req_vadr_x. i is the MC interface port number and x is changed in case of even or odd port.