[PATCH 2/3] ram: ast2600: Improve ddr4 timing and signal quality
Dylan Hung
dylan_hung at aspeedtech.com
Fri Nov 11 08:30:07 CET 2022
Adjust the following settings to get better timing and signal quality.
1. write DQS/DQ delay
- 1e6e2304[0]
- 1e6e2304[15:8]
2. read DQS/DQ delay
- 0x1e6e0298[0]
- 0x1e6e0298[15:8]
3. CLK/CA timing
- 0x1e6e01a8[31]
4. Read and write termination
- change RTT_ROM from 40 ohm to 48 ohm (MR1[10:8])
- change RTT_PARK from disable to 48 ohm (MR5[8:6])
- change RTT_WR from 120 ohm to disable (MR2[11:9])
- change PHY ODT from 40 ohm to 80 ohm (0x1e6e0130[10:8])
Note1: Both DDR-PHY and DDR controller have their own registers for DDR4
Mode Registers (MR0~MR6). This patch introduces macros to synchronize
the MR value on both sides.
Note2: the waveform meansurement can be found in item #21 of Aspeed
AST26x0 Application note (AP note).
Signed-off-by: Dylan Hung <dylan_hung at aspeedtech.com>
---
drivers/ram/aspeed/sdram_ast2600.c | 163 ++++++++++++++++++++++++-----
1 file changed, 138 insertions(+), 25 deletions(-)
diff --git a/drivers/ram/aspeed/sdram_ast2600.c b/drivers/ram/aspeed/sdram_ast2600.c
index b09232a30413..bda02d062900 100644
--- a/drivers/ram/aspeed/sdram_ast2600.c
+++ b/drivers/ram/aspeed/sdram_ast2600.c
@@ -20,6 +20,119 @@
#define DDR_PHY_TBL_CHG_ADDR 0xaeeddeea
#define DDR_PHY_TBL_END 0xaeededed
+/**
+ * phyr030[18:16] - Ron PU (PHY side)
+ * phyr030[14:12] - Ron PD (PHY side)
+ * b'000 : disable
+ * b'001 : 240 ohm
+ * b'010 : 120 ohm
+ * b'011 : 80 ohm
+ * b'100 : 60 ohm
+ * b'101 : 48 ohm
+ * b'110 : 40 ohm
+ * b'111 : 34 ohm (default)
+ */
+#define PHY_RON ((0x7 << 16) | (0x7 << 12))
+
+/**
+ * phyr030[10:8] - ODT configuration (PHY side)
+ * b'000 : ODT disabled
+ * b'001 : 240 ohm
+ * b'010 : 120 ohm
+ * b'011 : 80 ohm (default)
+ * b'100 : 60 ohm
+ * b'101 : 48 ohm
+ * b'110 : 40 ohm
+ * b'111 : 34 ohm
+ */
+#define PHY_ODT (0x3 << 8)
+
+/**
+ * MR1[2:1] output driver impedance
+ * b'00 : 34 ohm (default)
+ * b'01 : 48 ohm
+ */
+#define DRAM_RON (0x0 << 1)
+
+/**
+ * DRAM ODT - synchronous ODT mode
+ * RTT_WR: disable
+ * RTT_NOM = RTT_PARK
+ *
+ * MR1[10:8] RTT_NOM
+ * b'000 : RTT_NOM disable
+ * b'001 : 60 ohm
+ * b'010 : 120 ohm
+ * b'011 : 40 ohm
+ * b'100 : 240 ohm
+ * b'101 : 48 ohm (default)
+ * b'110 : 80 ohm
+ * b'111 : 34 ohm
+ *
+ * MR5[8:6] RTT_PARK
+ * b'000 : RTT_PARK disable
+ * b'001 : 60 ohm
+ * b'010 : 120 ohm
+ * b'011 : 40 ohm
+ * b'100 : 240 ohm
+ * b'101 : 48 ohm (default)
+ * b'110 : 80 ohm
+ * b'111 : 34 ohm
+ *
+ * MR2[11:9] RTT_WR
+ * b'000 : Dynamic ODT off (default)
+ * b'001 : 120 ohm
+ * b'010 : 240 ohm
+ * b'011 : Hi-Z
+ * b'100 : 80 ohm
+ */
+#define RTT_WR (0x0 << 9)
+#define RTT_NOM (0x5 << 8)
+#define RTT_PARK (0x5 << 6)
+
+/**
+ * MR6[6] VrefDQ training range
+ * b'0 : range 1
+ * b'1 : range 2 (default)
+ */
+#define VREFDQ_RANGE_2 BIT(6)
+
+/**
+ * Latency setting:
+ * AL = PL = 0 (hardware fixed setting)
+ * -> WL = AL + CWL + PL = CWL
+ * -> RL = AL + CL + PL = CL
+ */
+#define CONFIG_WL 9
+#define CONFIG_RL 12
+#define T_RDDATA_EN ((CONFIG_RL - 2) << 8)
+#define T_PHY_WRLAT (CONFIG_WL - 2)
+
+/* MR0 */
+#define MR0_CL_12 (BIT(4) | BIT(2))
+#define MR0_WR12_RTP6 BIT(9)
+#define MR0_DLL_RESET BIT(8)
+#define MR0_VAL (MR0_CL_12 | MR0_WR12_RTP6 | MR0_DLL_RESET)
+
+/* MR1 */
+#define MR1_VAL (0x0001 | RTT_NOM | DRAM_RON)
+
+/* MR2 */
+#define MR2_CWL_9 0
+#define MR2_VAL (0x0000 | RTT_WR | MR2_CWL_9)
+
+/* MR3 ~ MR6 */
+#define MR3_VAL 0x0000
+#define MR4_VAL 0x0000
+#define MR5_VAL (0x0400 | RTT_PARK)
+#define MR6_VAL 0x0400
+
+/**
+ * The offset value applied to the DDR PHY write data eye training result
+ * to fine-tune the write DQ/DQS alignment
+ */
+#define WR_DATA_EYE_OFFSET (0x10 << 8)
+
#if defined(CONFIG_ASPEED_DDR4_800)
u32 ast2600_sdramphy_config[165] = {
0x1e6e0100, // start address
@@ -35,7 +148,7 @@ u32 ast2600_sdramphy_config[165] = {
0x20000000, // phyr024
0x00000008, // phyr028
0x00000000, // phyr02c
- 0x00077600, // phyr030
+ (PHY_RON | PHY_ODT), /* phyr030 */
0x00000000, // phyr034
0x00000000, // phyr038
0x20000000, // phyr03c
@@ -44,18 +157,18 @@ u32 ast2600_sdramphy_config[165] = {
0x00002f07, // phyr048
0x00003080, // phyr04c
0x04000000, // phyr050
- 0x00000200, // phyr054
- 0x03140201, // phyr058
- 0x04800000, // phyr05c
- 0x0800044e, // phyr060
+ ((MR3_VAL << 16) | MR2_VAL), /* phyr054 */
+ ((MR0_VAL << 16) | MR1_VAL), /* phyr058 */
+ ((MR5_VAL << 16) | MR4_VAL), /* phyr05c */
+ ((0x0800 << 16) | MR6_VAL | VREFDQ_RANGE_2 | 0xe), /* phyr060 */
0x00000000, // phyr064
0x00180008, // phyr068
0x00e00400, // phyr06c
0x00140206, // phyr070
0x1d4c0000, // phyr074
- 0x493e0107, // phyr078
+ (0x493e0100 | T_PHY_WRLAT), /* phyr078 */
0x08060404, // phyr07c
- 0x90000a00, // phyr080
+ (0x90000000 | T_RDDATA_EN), /* phyr080 */
0x06420618, // phyr084
0x00001002, // phyr088
0x05701016, // phyr08c
@@ -94,7 +207,7 @@ u32 ast2600_sdramphy_config[165] = {
0x20202020, // phyr09c
0x20202020, // phyr0a0
0x00002020, // phyr0a4
- 0x80000000, // phyr0a8
+ 0x00000000, /* phyr0a8 */
0x00000001, // phyr0ac
0xaeeddeea, // change address
0x1e6e0318, // new address
@@ -154,7 +267,7 @@ u32 ast2600_sdramphy_config[165] = {
0x20202020, // phyr170
0xaeeddeea, // change address
0x1e6e0298, // new address
- 0x20200800, // phyr198
+ 0x20200000, /* phyr198 */
0x20202020, // phyr19c
0x20202020, // phyr1a0
0x20202020, // phyr1a4
@@ -177,7 +290,7 @@ u32 ast2600_sdramphy_config[165] = {
0x00002020, // phyr1e8
0xaeeddeea, // change address
0x1e6e0304, // new address
- 0x00000800, // phyr204
+ (0x00000001 | WR_DATA_EYE_OFFSET), /* phyr204 */
0xaeeddeea, // change address
0x1e6e027c, // new address
0x4e400000, // phyr17c
@@ -203,7 +316,7 @@ u32 ast2600_sdramphy_config[165] = {
0x20000000, // phyr024
0x00000008, // phyr028
0x00000000, // phyr02c
- 0x00077600, // phyr030
+ (PHY_RON | PHY_ODT), /* phyr030 */
0x00000000, // phyr034
0x00000000, // phyr038
0x20000000, // phyr03c
@@ -212,18 +325,18 @@ u32 ast2600_sdramphy_config[165] = {
0x00002f07, // phyr048
0x00003080, // phyr04c
0x04000000, // phyr050
- 0x00000200, // phyr054
- 0x03140501, // phyr058-rtt:40
- 0x04800000, // phyr05c
- 0x0800044e, // phyr060
+ ((MR3_VAL << 16) | MR2_VAL), /* phyr054 */
+ ((MR0_VAL << 16) | MR1_VAL), /* phyr058 */
+ ((MR5_VAL << 16) | MR4_VAL), /* phyr05c */
+ ((0x0800 << 16) | MR6_VAL | VREFDQ_RANGE_2 | 0xe), /* phyr060 */
0x00000000, // phyr064
0x00180008, // phyr068
0x00e00400, // phyr06c
0x00140206, // phyr070
0x1d4c0000, // phyr074
- 0x493e0107, // phyr078
+ (0x493e0100 | T_PHY_WRLAT), /* phyr078 */
0x08060404, // phyr07c
- 0x90000a00, // phyr080
+ (0x90000000 | T_RDDATA_EN), /* phyr080 */
0x06420c30, // phyr084
0x00001002, // phyr088
0x05701016, // phyr08c
@@ -256,13 +369,13 @@ u32 ast2600_sdramphy_config[165] = {
0x00000000, // phyr200
0xaeeddeea, // change address
0x1e6e0194, // new address
- 0x801112e0, // phyr094 - bit12=1,15=0,- write window is ok
+ 0x801112e0, // phyr094
0xaeeddeea, // change address
0x1e6e019c, // new address
0x20202020, // phyr09c
0x20202020, // phyr0a0
0x00002020, // phyr0a4
- 0x80000000, // phyr0a8
+ 0x00000000, /* phyr0a8 */
0x00000001, // phyr0ac
0xaeeddeea, // change address
0x1e6e0318, // new address
@@ -322,7 +435,7 @@ u32 ast2600_sdramphy_config[165] = {
0x20202020, // phyr170
0xaeeddeea, // change address
0x1e6e0298, // new address
- 0x20200800, // phyr198
+ 0x20200000, /* phyr198 */
0x20202020, // phyr19c
0x20202020, // phyr1a0
0x20202020, // phyr1a4
@@ -345,7 +458,7 @@ u32 ast2600_sdramphy_config[165] = {
0x00002020, // phyr1e8
0xaeeddeea, // change address
0x1e6e0304, // new address
- 0x00000800, // phyr204
+ (0x00000001 | WR_DATA_EYE_OFFSET), /* phyr204 */
0xaeeddeea, // change address
0x1e6e027c, // new address
0x4e400000, // phyr17c
@@ -388,10 +501,10 @@ u32 ast2600_sdramphy_config[165] = {
* AC timing and SDRAM mode register setting
* for real chip are derived from the model GDDR4-1600
*/
-#define DDR4_MR01_MODE 0x03010510
-#define DDR4_MR23_MODE 0x00000000
-#define DDR4_MR45_MODE 0x04000000
-#define DDR4_MR6_MODE 0x00000400
+#define DDR4_MR01_MODE ((MR1_VAL << 16) | MR0_VAL)
+#define DDR4_MR23_MODE ((MR3_VAL << 16) | MR2_VAL)
+#define DDR4_MR45_MODE ((MR5_VAL << 16) | MR4_VAL)
+#define DDR4_MR6_MODE MR6_VAL
#define DDR4_TRFC_1600 0x467299f1
#define DDR4_TRFC_1333 0x3a5f80c9
#define DDR4_TRFC_800 0x23394c78
--
2.25.1
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