powerpc/8xxx: Enabled hwconfig for memory interleaving
[kernel/u-boot.git] / doc / README.fsl-ddr
1
2 Table of interleaving modes supported in cpu/8xxx/ddr/
3 ======================================================
4   +-------------+---------------------------------------------------------+
5   |             |                   Rank Interleaving                     |
6   |             +--------+-----------+-----------+------------+-----------+
7   |Memory       |        |           |           |    2x2     |    4x1    |
8   |Controller   |  None  | 2x1 lower | 2x1 upper | {CS0+CS1}, | {CS0+CS1+ |
9   |Interleaving |        | {CS0+CS1} | {CS2+CS3} | {CS2+CS3}  |  CS2+CS3} |
10   +-------------+--------+-----------+-----------+------------+-----------+
11   |None         |  Yes   | Yes       | Yes       | Yes        | Yes       |
12   +-------------+--------+-----------+-----------+------------+-----------+
13   |Cacheline    |  Yes   | Yes       | No        | No, Only(*)| Yes       |
14   |             |CS0 Only|           |           | {CS0+CS1}  |           |
15   +-------------+--------+-----------+-----------+------------+-----------+
16   |Page         |  Yes   | Yes       | No        | No, Only(*)| Yes       |
17   |             |CS0 Only|           |           | {CS0+CS1}  |           |
18   +-------------+--------+-----------+-----------+------------+-----------+
19   |Bank         |  Yes   | Yes       | No        | No, Only(*)| Yes       |
20   |             |CS0 Only|           |           | {CS0+CS1}  |           |
21   +-------------+--------+-----------+-----------+------------+-----------+
22   |Superbank    |  No    | Yes       | No        | No, Only(*)| Yes       |
23   |             |        |           |           | {CS0+CS1}  |           |
24   +-------------+--------+-----------+-----------+------------+-----------+
25  (*) Although the hardware can be configured with memory controller
26  interleaving using "2x2" rank interleaving, it only interleaves {CS0+CS1}
27  from each controller. {CS2+CS3} on each controller are only rank
28  interleaved on that controller.
29
30 The ways to configure the ddr interleaving mode
31 ==============================================
32 1. In board header file(e.g.MPC8572DS.h), add default interleaving setting
33    under "CONFIG_EXTRA_ENV_SETTINGS", like:
34         #define CONFIG_EXTRA_ENV_SETTINGS                               \
35          "hwconfig=fsl_ddr:ctlr_intlv=bank"                     \
36          ......
37
38 2. Run u-boot "setenv" command to configure the memory interleaving mode.
39    Either numerical or string value is accepted.
40
41   # disable memory controller interleaving
42   setenv hwconfig "fsl_ddr:ctlr_intlv=null"
43
44   # cacheline interleaving
45   setenv hwconfig "fsl_ddr:ctlr_intlv=cacheline"
46
47   # page interleaving
48   setenv hwconfig "fsl_ddr:ctlr_intlv=page"
49
50   # bank interleaving
51   setenv hwconfig "fsl_ddr:ctlr_intlv=bank"
52
53   # superbank
54   setenv hwconfig "fsl_ddr:ctlr_intlv=superbank"
55
56   # disable bank (chip-select) interleaving
57   setenv hwconfig "fsl_ddr:bank_intlv=null"
58
59   # bank(chip-select) interleaving cs0+cs1
60   setenv hwconfig "fsl_ddr:bank_intlv=cs0_cs1"
61
62   # bank(chip-select) interleaving cs2+cs3
63   setenv hwconfig "fsl_ddr:bank_intlv=cs2_cs3"
64
65   # bank(chip-select) interleaving (cs0+cs1) and (cs2+cs3)  (2x2)
66   setenv hwconfig "fsl_ddr:bank_intlv=cs0_cs1_and_cs2_cs3"
67
68   # bank(chip-select) interleaving (cs0+cs1+cs2+cs3) (4x1)
69   setenv hwconfig "fsl_ddr:bank_intlv=cs0_cs1_cs2_cs3"
70
71   The above memory controller interleaving and bank interleaving can be mixed. The syntax is
72   setenv hwconfig "fsl_ddr:ctlr_intlv=cacheline,bank_intlv=cs0_cs1"