ZHCS488K October 2011 – December 2018 AM3351 , AM3352 , AM3354 , AM3356 , AM3357 , AM3358 , AM3359
PRODUCTION DATA.
Signal terminations are required on the CK and ADDR_CTRL net class signals. Serial terminations should be used on the CK and ADDR_CTRL lines and is the preferred termination scheme. On-device terminations (ODTs) are required on the DQS[x] and DQ[x] net class signals. They should be enabled to ensure signal integrity. Table 7-54 shows the specifications for the series terminators. Placement of serial terminations for ADDR_CTRL net class signals should be close to the AM335x device.
NO. | PARAMETER | MIN | TYP | MAX | UNIT |
---|---|---|---|---|---|
1 | CK net class(1) | 0 | 10 | Ω | |
2 | ADDR_CTRL net class(1)(2)(3) | 0 | 22 | Zo(4) | Ω |
3 | DQS0, DQS1, DQ0, and DQ1 net classes(5) | N/A | N/A | Ω |
If the DDR2 interface is operated at a lower frequency (<200-MHz clock rate), on-device terminations are not specifically required for the DQS[x] and DQ[x] net class signals and serial terminations for the CK and ADDR_CTRL net class signals are not mandatory. System designers may evaluate the need for serial terminators for EMI and overshoot reduction. Placement of serial terminations for DQS[x] and DQ[x] net class signals should be determined based on PCB analysis. Placement of serial terminations for ADDR_CTRL net class signals should be close to the AM335x device. Table 7-55 shows the specifications for the serial terminators in such cases.
NO. | PARAMETER | MIN | TYP | MAX | UNIT |
---|---|---|---|---|---|
1 | CK net class(1) | 0 | 22 | Zo(2) | Ω |
2 | ADDR_CTRL net class(1)(3)(4) | 0 | 22 | Zo(2) | Ω |
3 | DQS0, DQS1, DQ0, and DQ1 net classes | 0 | 22 | Zo(2) | Ω |