| Signal | Type | Description |
| CLK | Input | Clock signal. |
| RST_L | Input | Reset signal. |
| SDRAM_SETUP | Input | Indicates SDRAM setup is complete. |
| SDRAM_CYCLE [3:0] | Input | State machine bits—indicates the type of cycle: 00 = idle, 01 = command, 10 = data, 11 = refresh. |
| RFRSH_REQ | Output | Refresh cycle request to state machine. |