STM32MP157F板无法进行DQS计时这到底是什么意思？

我正在 DDR 调整带有 4GB DDR3 的定制 STM32MP157F 板。所有 DDR 测试都通过了，但是我得到以下位偏斜调整失败： 失败 [无法对线进行偏斜校正，没有通过区域]和眼部训练：  [无法进行 DQS 计时，没有通过区域]
这到底是什么意思？怎么调优不通过，测试通过呢？

• DDR>test 0
• ...
• loop 1: 0/17 test failed
• Result: Pass [loop 1: 17 tests passed]
• DDR>tuning 1
• execute 1:Bit de-skew
• Result: Failed [Cannot Deskew lines, there is no PASS region]
• Result: Failed [Cannot Deskew lines, there is no PASS region]
• Result: Failed [error = 2]
• DDR>tuning 2
• execute 2:Eye Training
• Result: Failed [Cannot DQS timings, there is no PASS region]
• Byte 1, DQS unit = 3, phase = 3
• Result: Failed [error = 1]
• DDR>tuning 3
• execute 3:Display registers
• Byte 0 Dekew result, bit0 delay, bit1 delay...bit8 delay
•   2 2 2 2 2 2 2 2
• dxndllcr: [5a0041cc] val:400a0000
• dxnqdstr: [5a0041d4] val:3db02001
• dxndqtr: [5a0041d0] val:aaaaaaaa
• Byte 1 Dekew result, bit0 delay, bit1 delay...bit8 delay
•   2 2 2 2 2 2 2 2
• dxndllcr: [5a00420c] val:40000000
• dxnqdstr: [5a004214] val:3db02001
• dxndqtr: [5a004210] val:aaaaaaaa
• Result: Pass []
• DDR>tuning 4
• execute 4:Bist config
• Bist.nbErr = 1
• Bist.Seed = 0x1234abcd
• Result: Pass []