3.6.3 MPDDRC Configuration Register
This register can only be written if the WPEN bit is cleared in the MPDDRC Write Protection Mode Register.
| Name: | MPDDRC_CR |
| Offset: | 0x08 |
| Reset: | 0x00207024 |
| Property: | Read/Write |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| CAS_WR[2:0] | |||||||||
| Access | R/W | R/W | R/W | ||||||
| Reset | 0 | 0 | 0 | ||||||
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| UNAL | DECOD | NDQS | NB | DQMS | |||||
| Access | R/W | R/W | R/W | R/W | R/W | ||||
| Reset | 0 | 0 | 1 | 0 | 0 |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| SUP_DDR3 | OCD[2:0] | DIS_DLL | DIC_DS | ||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
| Reset | 0 | 1 | 1 | 1 | 0 | 0 | |||
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| DLL | CAS[2:0] | NR[1:0] | NC[1:0] | ||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | |
Bits 28:26 – CAS_WR[2:0] CAS Write Latency
| Value | Name | Description |
|---|---|---|
| 5 | DDR3_CAS5 | DDR3 CAS write latency 5, DLL must be enabled, DLL On mode |
| 6 | DDR3_CAS6 | DDR3 CAS write latency 6, DLL enabled or not, DLL On/Off mode |
Bit 23 – UNAL This bit must always be written to 1.
Bit 22 – DECOD Type of Decoding
| Value | Name | Description |
|---|---|---|
| 0 | SEQUENTIAL | Method for address mapping where banks alternate at each last DDR-SDRAM page of the current bank. |
| 1 | INTERLEAVED | Method for address mapping where banks alternate at each DDR-SDRAM end of page of the current bank. |
Bit 21 – NDQS Not DQS.
This bit is found in DDR2-SDRAM devices, in Extended Mode register 1. DQS may be used in Single-ended mode or paired with optional complementary signal NDQS.
| Value | Name | Description |
|---|---|---|
| 0 | ENABLED | 'Not DQS' is enabled. |
| 1 | DISABLED | 'Not DQS' is disabled. |
Bit 20 – NB Number of Banks
| Value | Name | Description |
|---|---|---|
| 0 | 4_BANKS | 4-bank memory devices |
| 1 | 8_BANKS | 8 banks. Only possible when using DDR2-SDRAM,, DDR3-SDRAM devices. |
Bit 16 – DQMS Mask Data is Shared
| Value | Name | Description |
|---|---|---|
| 0 | NOT_SHARED | DQM is not shared with another controller |
| 1 | SHARED | DQM is shared with another controller |
Bit 15 – SUP_DDR3 Supply DDR3-SDRAM or DDR3L-SDRAM
This value is used during the power-up sequence.
| Value | Description |
|---|---|
| 0 | 1.35V DDR3L-SDRAM is used. |
| 7 | 1.5V DDR3-SDRAM is used. |
Bits 14:12 – OCD[2:0] Off-chip Driver
SDRAM Controller supports only two values for OCD (default calibration and exit from calibration). These values MUST always be programmed during the initialization sequence. The default calibration must be programmed first, after which the exit calibration and maintain settings must be programmed.
This field is found only in the DDR2-SDRAM devices.
| Value | Name | Description |
|---|---|---|
| 0 | DDR2_EXITCALIB | Exit from OCD Calibration mode and maintain settings |
| 7 | DDR2_DEFAULT_CALIB | OCD calibration default |
Bit 9 – DIS_DLL Disable DLL
This value is used during the power-up sequence. It is only found in DDR2-SDRAM devices and DDR3-SDRAM devices.
| Value | Description |
|---|---|
| 0 | Enable DLL. |
| 1 | Disable DLL. |
Bit 8 – DIC_DS Output Driver Impedance Control (Drive Strength)
This bit name is described as “DS” in some memory data sheets. It defines the output drive strength. This value is used during the power-up sequence.
For DDR3-SDRAM devices, this field is equivalent to ODS, Output Drive Strength.
This bit is found only in DDR2-SDRAM devices and DDR3-SDRAM devices.
| Value | Name | Description |
|---|---|---|
| 0 | DDR2_NORMALSTRENGTH_DDR3_RZQ_6 | Normal drive strength (DDR2) - RZQ_6 (40 [NOM], DDR3) |
| 1 | DDR2_WEAKSTRENGTH_DDR3_RZQ_7 | Weak drive strength (DDR2) - RZQ_7 (34 [NOM], DDR3) |
Bit 7 – DLL Reset DLL
This bit defines the value of Reset DLL. It is found only in DDR2-SDRAM and DDR3-SDRAM devices.
This value is used during the power-up sequence.
| Value | Name | Description |
|---|---|---|
| 0 | RESET_DISABLED | Disable DLL reset |
| 1 | RESET_ENABLED | Enable DLL reset |
Bits 6:4 – CAS[2:0] CAS Latency
| Value | Name | Description |
|---|---|---|
| 3 | DDR_CAS3 | DDR2 CAS Latency 3 |
| 4 | DDR_CAS4 | DDR2 CAS Latency 4 |
| 5 | DDR_CAS5 | DDR2/DDR3 CAS Latency 5 |
| 6 | DDR_CAS6 | DDR3 CAS Latency 6 |
Bits 3:2 – NR[1:0] Number of Row Bits
| Value | Name | Description |
|---|---|---|
| 0 | 11_ROW_BITS | 11 bits to define the row number, up to 2048 rows |
| 1 | 12_ROW_BITS | 12 bits to define the row number, up to 4096 rows |
| 2 | 13_ROW_BITS | 13 bits to define the row number, up to 8192 rows |
| 3 | 14_ROW_BITS | 14 bits to define the row number, up to 16384 rows |
Bits 1:0 – NC[1:0] Number of Column Bits
| Value | Name | Description |
|---|---|---|
| 0 | 9_COL_BITS | 9 bits to define the column number, up to 512 columns, for DDR2/DDR3-SDRAM |
| 1 | 10_COL_BITS | 10 bits to define the column number, up to 1024 columns, for DDR2/DDR3-SDRAM |
| 2 | 11_COL_BITS | 11 bits to define the column number, up to 2048 columns, for DDR2/DDR3-SDRAM |
| 3 | 12_COL_BITS | 12 bits to define the column number, up to 4096 columns, for DDR2/DDR3-SDRAM |