AM6421 datasheet(222/237 Pages) TI

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– A to B = E to F = (C to D) / 2

– Matching skew: < 60 ps

Note

The OSPI Board Loopback Hold time requirement (described in Section 7.10.5.14, OSPI) is larger

than the Hold time provided by a typical flash device. Therefore, the length of MCU_OPSI[x]_LBCLKO

pin to the MCU_OSPI[x]_DQS pin (C to D) can be shortened to compensate.

MCU_OSPI[x]_CLK

OSPI/QSPI/SPI

device clock input

OSPI/QSPI/SPI

device IOy, CS#

MCU_OSPI[x]_D[y],

MCU_OSPI[x]_CSn[z]

OSPI_Board_02

MCU_OSPI[x]_LBCLKO

MCU_OSPI[x]_DQS

* 0 Ω resistor (R1), located as close as possible to the MCU_OSPI[x]_CLK and MCU_OSPI[x]_LBCLKO pins, is a placeholder for fine

tuning, if needed.

Figure 9-2. OSPI Interface High Level Schematic

9.3.2.3 DQS (only available in Octal Flash devices)

• The MCU_OSPI[x]_CLK output signal must be connected to the CLK pin of the flash device

• The DQS pin of the flash devices must be connected to MCU_OSPI[x]_DQS signal

• The signal propagation delay from the MCU_OSPI[x]_CLK pin to the flash device CLK input pin (A to B)

should be approximately equal to the signal propagation delay from the MCU_OSPI[x]_DQS pin to the DQS

output pin (C to D)

• 50 Ω PCB routing is recommended along with series terminations, as shown in Figure 9-3

• Propagation delays and matching:

– A to B = C to D

AM6442, AM6441, AM6421

AM6412, AM6411

SPRSP56 – JANUARY 2021

www.ti.com

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Product Folder Links: AM6442 AM6441 AM6421 AM6412 AM6411

AM6421 Datasheet(PDF) 222 Page - Texas Instruments