ZHCSJ47E March 2017 – December 2018 DRA76P , DRA77P
ADVANCE INFORMATION for pre-production products; subject to change without notice.
Figure 7-52 shows the topology of the routing for the CK and ADDR_CTRL net classes. The route is a balanced T as it is intended that the length of segments B and C be equal. In addition, the length of A = (A'+A'') should be maximized.
Figure 7-52 CK and ADDR_CTRL Routing and Topology | NO. | PARAMETER | MIN | MAX | UNIT |
|---|---|---|---|---|
| RSC21 | Center-to-center ddrx_ck - ddrx_nck spacing | 2w | ||
| RSC22 | ddrx_ck / ddrx_nck skew(1) | 5 | ps | |
| RSC23 | CK A-to-B/A-to-C skew mismatch(2) | 10 | ps | |
| RSC24 | CK B-to-C skew mismatch | 10 | ps | |
| RSC25 | Center-to-center CK to other DDR2 trace spacing(3) | 4w | ||
| RSC26 | CK/ADDR_CTRL trace length(4) | 680 | ps | |
| RSC27 | ADDR_CTRL-to-CK skew mismatch | 25 | ps | |
| RSC28 | ADDR_CTRL-to-ADDR_CTRL skew mismatch | 25 | ps | |
| RSC29 | Center-to-center ADDR_CTRL to other DDR2 trace spacing(3) | 4w | ||
| RSC210 | Center-to-center ADDR_CTRL to other ADDR_CTRL trace spacing(3) | 3w | ||
| RSC211 | ADDR_CTRL A-to-B/A-to-C skew mismatch(2)(5) | 25 | ps | |
| RSC212 | ADDR_CTRL B-to-C skew mismatch(5) | 25 | ps |
Figure 7-53 shows the topology and routing for the DQS and DQ net classes; the routes are point to point. Skew matching across bytes is not needed nor recommended.
Figure 7-53 DQS and DQ Routing and Topology | NO. | PARAMETER | MIN | MAX | UNIT |
|---|---|---|---|---|
| RSDQ21 | Center-to-center DQS-DQSn spacing in E0|E1|E2|E3 | 2w | ||
| RSDQ22 | DQS-DQSn skew in E0|E1|E2|E3 | 5 | ps | |
| RSDQ23 | Center-to-center DQS to other DDR2 trace spacing(1) | 4w | ||
| RSDQ24 | DQS/DQ trace length (2)(3)(4) | 325 | ps | |
| RSDQ25 | DQ-to-DQS skew mismatch(2)(3)(4) | 10 | ps | |
| RSDQ26 | DQ-to-DQ skew mismatch(2)(3)(4) | 10 | ps | |
| RSDQ27 | DQ-to-DQ/DQS via count mismatch(2)(3)(4) | 1 | Vias | |
| RSDQ28 | Center-to-center DQ to other DDR2 trace spacing(1)(5) | 4w | ||
| RSDQ29 | Center-to-center DQ to other DQ trace spacing(1)(6)(7) | 3w | ||
| RSDQ210 | DQ/DQS E skew mismatch(2)(3)(4) | 25 | ps |