6.6.1 DDR3 PLL Control Register
The DDR3 PLL, which is used to drive the DDR PHY for the EMIF, does not use a PLL controller. The DDR3 PLL can be controlled using the DDR3PLLCTL0 and DDR3PLLCTL1 Registers in the Bootcfg module. These MMRs exist inside the Bootcfg space. To write to these registers, software should go through an unlocking sequence using the KICK0/KICK1 registers. For suggested configurable values, see Section 8.3.4 for the address location of the registers and locking and unlocking sequences for accessing the registers. This register is reset on POR only. DDR3PLLCTL0 is shown in Figure 6-16 and described in Table 6-21. DDR3PLLCTL1 is shown in Figure 6-17 and described in Table 6-22.
Figure 6-16 DDR3 PLL Control Register 0 (DDR3PLLCTL0)(1)
BWADJ[7:0] |
BYPASS |
Reserved |
PLLM |
PLLD |
RW,+0000 1001 |
RW,+0 |
RW,+0001 |
RW,+0000000010011 |
RW,+000000 |
Legend: RW = Read/Write; -n = value after reset |
(1) This register is Reset on POR only. The regreset, reset and bgreset from PLL are all tied to a common pll0_ctrl_rst_n The pwrdn, regpwrdn, bgpwrdn are all tied to common pll0_ctrl_to_pll_pwrdn.
Table 6-21 DDR3 PLL Control Register 0 Field Descriptions
BIT |
FIELD |
DESCRIPTION |
31-24 |
BWADJ[7:0] |
BWADJ[11:8] and BWADJ[7:0] are located in DDR3PLLCTL0 and DDR3PLLCTL1 registers. The combination (BWADJ[11:0]) should be programmed to a value related to PLLM[12:0] value based on the equation: BWADJ = ((PLLM+1)>>1) -1 |
23 |
BYPASS |
Enable bypass mode
- 0 = Bypass disabled
- 1 = Bypass enabled
|
22-19 |
Reserved |
Reserved |
18-6 |
PLLM |
A 13-bit bus that selects the values for the multiplication factor |
5-0 |
PLLD |
A 6-bit bus that selects the values for the reference divider |
Figure 6-17 DDR3 PLL Control Register 1 (DDR3PLLCTL1)
Reserved |
PLLRST |
Reserved |
ENSAT |
Reserved |
BWADJ[11:8] |
RW-000000000000000000 |
RW-0 |
RW-000000 |
RW-0 |
R-0 |
RW-0000 |
Legend: RW = Read/Write; -n = value after reset |
Table 6-22 DDR3 PLL Control Register 1 Field Descriptions
BIT |
FIELD |
DESCRIPTION |
31-14 |
Reserved |
Reserved |
13 |
PLLRST |
PLL reset bit.
- 0 = PLL reset is released.
- 1 = PLL reset is asserted.
|
12-7 |
Reserved |
Reserved |
6 |
ENSAT |
Needs to be set to 1 for proper operation of the PLL |
5-4 |
Reserved |
Reserved |
3-0 |
BWADJ[11:8] |
BWADJ[11:8] and BWADJ[7:0] are located in separate registers. The combination (BWADJ[11:0]) should be programmed to a value related to PLLM[12:0] value based on the equation: BWADJ = ((PLLM+1)>>1) -1 |