TMS320DM814X datasheet(321/376 Pages) TI1

321 / 376 page

Rtt

Vtt

(A)

CACLMX

CACLMY

Rtt

Vtt

(A)

CACLMX

CACLMY

TMS320DM8148, TMS320DM8147

www.ti.com

SPRS647E – MARCH 2011 – REVISED DECEMBER 2013

It is very likely that the longest CK/ADDR_CTRL Manhattan distance will be for Address Input 8 (A8) on the DDR3

memories. CACLM is based on the longest Manhattan distance due to the device placement. Verify the net class that

satisfies this criteria and use as the baseline for CK/ADDR_CTRL skew matching and length control.

The length of shorter CK/ADDR_CTRL stubs as well as the length of the terminator stub are not included in this

length calculation. Non-included lengths are grayed out in the figure.

Assuming A8 is the longest, CALM = CACLMY + CACLMX + 300 mils.

The extra 300 mils allows for routing down lower than the DDR3 memories and returning up to reach A8.

Figure 8-78. CACLM for Four Address Loads on One Side of PCB

It is very likely that the longest CK/ADDR_CTRL Manhattan distance will be for Address Input 8 (A8) on the DDR3

memories. CACLM is based on the longest Manhattan distance due to the device placement. Verify the net class that

satisfies this criteria and use as the baseline for CK/ADDR_CTRL skew matching and length control.

The length of shorter CK/ADDR_CTRL stubs as well as the length of the terminator stub are not included in this

length calculation. Non-included lengths are grayed out in the figure.

Assuming A8 is the longest, CALM = CACLMY + CACLMX + 300 mils.

The extra 300 mils allows for routing down lower than the DDR3 memories and returning up to reach A8.

Figure 8-79. CACLM for Two Address Loads on One Side of PCB

Peripheral Information and Timings

321

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TMS320DM814x Datasheet(PDF) 321 Page - Texas Instruments