SPRUHZ7K August 2015 – April 2024 AM5706 , AM5708 , AM5716 , AM5718 , AM5718-HIREL
On coming out of reset, the EMIF controller begins the DDR3 initialization sequence after a write to any one of the following three registers, providing that the corresponding listed conditions are met:
For the first DDR3 initialization sequence, the EMIF controller performs the following actions:
| Bits | Value | Description |
|---|---|---|
| A[15:11] | 0x0 | Reserved |
| A[10:9] | EMIF_SDRAM_CONFIG[22:21] DYN_ODT | Dynamic ODT value |
| A[8] | 0x0 | Reserved |
| A[7] | EMIF_SDRAM_REFRESH_CONTROL[29] SRT | Self-refresh temperature range |
| A[6] | EMIF_SDRAM_REFRESH_CONTROL[28] ASR | Auto self-refresh enable |
| A[5] | 0x0 | Reserved |
| A[4:3] | EMIF_SDRAM_CONFIG[17:16] CWL | CAS write latency |
| A[2:0] | EMIF_SDRAM_REFRESH_CONTROL[26:24] PASR | Partial array self-refresh |
| Bits | Value | Description |
|---|---|---|
| A[15:13] | 0x0 | Reserved |
| A[12] | 0x0 | Output buffer enabled |
| A[11] | 0x0 | TDQS disable |
| A[10] | 0x0 | Reserved |
| A[9], A[6], A[2] | EMIF_SDRAM_CONFIG[26:24] DDR_TERM | DDR3/DDR3L termination resistor value |
| A[8] | 0x0 | Reserved |
| A[7] | 0x0 | Write leveling disabled |
| A[5], A[1] | EMIF_SDRAM_CONFIG[19:18] SDRAM_DRIVE | SDRAM drive strength |
| A[4:3] | 0x0 | Additive latency = 0 |
| A[0] | EMIF_SDRAM_CONFIG[20] DDR_DISABLE_DLL = 0x0 | Enable SDRAM DLL |
| Bits | Value | Description |
|---|---|---|
| A[15:13] | 0x0 | Reserved |
| A[12] | 0x0 | Slow exit. The DDR3/DDR3L SDRAM DLL is “OFF” after entering precharge power-down. |
| A[11:9] | EMIF_SDRAM_TIMING_1[20:17] T_WR | Write recovery for autoprecharge |
| A[8] | 0x1 | DLL reset |
| A[7] | 0x0 | Normal mode |
| A[6:4], A[2] | EMIF_SDRAM_CONFIG[13:10] CL | Value for CAS latency |
| A[3] | 0x0 | Nibble sequential read burst type |
| A[1:0] | 0x0 | Burst length of 8 |
The EMIF updates the DDR Mode registers if the DDR3 initialization sequence is triggered again. However, the EMIF controller first issues a precharge command and then starts from Step 3.
The EMIF does not perform any transactions until the DDR3/DDR3L initialization sequence is complete.
When the EMIF comes out of reset, the delay time in Step 2 resulting from the 16 refresh rate intervals + 8 cycles is approximately 16 × REFRESH_RATE / input frequency.