Functional Description
9.2.5 DDR PHY
Table 9-7. DDR Slew Rate Control Settings
(1) (2)
Turn-on Time for Drv8
Max Noise on IO
Turn-on
sr0
sr1
Interface
Setting
Supply for Drv8 Setting
Time Level
(ps)
(3)
(4)
1.5 V
117
0.43
0
0
Fastest
1.8 V
116
0.6
1.5 V
430
0.17
0
1
Fast
1.8 V
443
0.24
1.5 V
530
0.15
1
0
Slow
1.8 V
567
0.21
1.5 V
790
0.13
1
1
Slowest
1.8 V
815
0.18
(1)
These values are programmed in the following registers: ddr_cmd0_ioctrl, ddr_cmd1_ioctrl, ddr_cmd2_ioctrl, ddr_data0_ioctrl,
ddr_data1_ioctrl.
(2)
Values for DDR_CMDx_IOCTRL.io_config_sr_clk should be programmed to the same value.
(3)
Value is obtained at nominal PTV.
(4)
Value is the average across PTVs.
Table 9-8. DDR Impedance Control Settings
(1) (2) (3)
Example:
Output
Example:
Drive Setting
Drive Strength
|I
OH
|, |I
OL
| for R
ext
I2
I1
I0
Impedance
R
on
for R
ext
=
Name
|I
OH
|, |I
OL
|
=
(R
on
)
49.9 ohms
49.9 ohms
0
0
0
Drv5
1.6*R
ext
0.625*I
out
80 ohms
5 mA
0
0
1
Drv6
1.33*R
ext
0.75*I
out
67 ohms
6 mA
0
1
0
Drv7
1.14*R
ext
0.875*I
out
57 ohms
7 mA
0
1
1
Drv8
R
ext
I
out
50 ohms
8 mA
1
0
0
Drv9
0.88*R
ext
1.125*I
out
44 ohms
9 mA
1
0
1
Drv10
0.8*R
ext
1.250*I
out
40 ohms
10 mA
1
1
0
Drv11
0.73*R
ext
1.375*I
out
36 ohms
11 mA
1
1
1
Drv12
0.67*R
ext
1.5*I
out
33 ohms
12 mA
(1)
These values are programmed in the following registers: ddr_cmd0_ioctrl, ddr_cmd1_ioctrl, ddr_cmd2_ioctrl, ddr_data0_ioctrl,
ddr_data1_ioctrl.
(2)
Values for DDR_CMDx_IOCTRL.io_config_i_clk should be programmed to the same value.
(3)
R
ext
is the external VTP compensation resistor connected to DDR_VTP terminal.
9.2.5.1
DDR PHY to IO Pin Mapping
The following table describes the DDR PHY to IO pin mapping.
Table 9-9. DDR PHY to IO Pin Mapping
Macro Pin
CMD0
CMD1
CMD2
DATA0
DATA1
0
ddr_ba2
Unconn
ddr_cke
ddr_d8
ddr_d0
1
ddr_wen
ddr_a15
ddr_resetn
ddr_d9
ddr_d1
2
ddr_ba0
ddr_a2
ddr_odt
ddr_d10
ddr_d2
3
ddr_a5
ddr_a12
Unconn
ddr_d11
ddr_d3
4
ddr_ck
ddr_a7
ddr_a14
ddr_d12
ddr_d4
5
ddr_ckn
ddr_ba1
ddr_a13
ddr_d13
ddr_d5
6
ddr_a3
ddr_a10
ddr_csn0
ddr_d14
ddr_d6
7
ddr_a4
ddr_a0
Unconn
ddr_d15
ddr_d7
8
ddr_a8
ddr_a11
ddr_a1
ddr_dqm1
ddr_dqm0
756 Control Module
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated