EMIF
7.3.5.34 DDR_PHY_CTRL_1_SHDW Register (offset = E8h) [reset = 0h]
DDR_PHY_CTRL_1_SHDW is shown in
and described in
.
A write to the DDR PHY Control 1 register must be followed by a write to the SDRAM_CONFIG register to
ensure that the control update/acknowledge protocol is performed on the DID. If CAS latency = 5, the
minimum read latency = 5 + 2 = 7 and reg_read_latency must be programmed as 7 - 1 = 6. The maximum
read latency = 5 + 7 = 12 and reg_read_latency must be programmed as 12 - 1 = 11.
Figure 7-124. DDR_PHY_CTRL_1_SHDW Register
31
30
29
28
27
26
25
24
Reserved
R/W-0h
23
22
21
20
19
18
17
16
Reserved
reg_phy_enable_dyna
Reserved
mic_pwrdn
R/W-0h
R/W-1h
R/W-0h
15
14
13
12
11
10
9
8
reg_phy_rst_n
Reserved
reg_phy_idle_local_odt
reg_phy_wr_local_odt
reg_phy_rd_local_odt
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
Reserved
reg_read_latency
R/W-0h
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 7-144. DDR_PHY_CTRL_1_SHDW Register Field Descriptions
Bit
Field
Type
Reset
Description
31-21
Reserved
R/W
0h
Reserved.
20
reg_phy_enable_dynamic
R/W
1h
Dynamically enables powering down the IO receiver when not
_pwrdn
performing a read.
0 = IO receivers always powered up.
1 = IO receivers only powered up during a read.
19-16
Reserved
R/W
0h
Reserved.
15
reg_phy_rst_n
R/W
0h
Writing a 1 to this bit will hold the PHY macros in reset.
Writing a 0 will bring PHY macros out of reset.
14
Reserved
R/W
0h
Reserved.
13-12
reg_phy_idle_local_odt
R/W
0h
Value to drive on the
2-bit local_odt PHY outputs when reg_phy_dynamic_pwrdn_enable
is asserted and a read is not in progress and
reg_phy_dynamic_pwrdn_enable.
Typically this is the value required to disable termination (00) to save
power when idle.
11-10
reg_phy_wr_local_odt
R/W
0h
This bit controls the value assigned to the reg_phy_wr_local_odt
input on the data macros.
Always set to 00.
9-8
reg_phy_rd_local_odt
R/W
0h
Value to drive on the
2-bit local_odt PHY outputs when output enable is not asserted and
a read is in progress (where in progress is defined as after a read
command is issued and until all read data has been returned all the
way to the controller.) Typically this is set to the value required to
enable termination at the desired strength for read usage.
00 = ODT off.
01 = ODT off.
10 = Full thevenin load.
11 = Half thevenin load.
7-5
Reserved
R/W
0h
Reserved.
460
Memory Subsystem
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated