NXP Semiconductors /MIMXRT1021 /FLEXSPI /AHBCR

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Interpret as AHBCR

31 2827 2423 2019 1615 1211 87 43 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (APAREN_0)APAREN 0 (CACHABLEEN_0)CACHABLEEN 0 (BUFFERABLEEN_0)BUFFERABLEEN 0 (PREFETCHEN)PREFETCHEN 0 (READADDROPT_0)READADDROPT

CACHABLEEN=CACHABLEEN_0, APAREN=APAREN_0, BUFFERABLEEN=BUFFERABLEEN_0, READADDROPT=READADDROPT_0

Description

AHB Bus Control Register

Fields

APAREN

Parallel mode enabled for AHB triggered Command (both read and write) .

0 (APAREN_0): Flash will be accessed in Individual mode.

1 (APAREN_1): Flash will be accessed in Parallel mode.

CACHABLEEN

Enable AHB bus cachable read access support.

0 (CACHABLEEN_0): Disabled. When there is AHB bus cachable read access, FlexSPI will not check whether it hit AHB TX Buffer.

1 (CACHABLEEN_1): Enabled. When there is AHB bus cachable read access, FlexSPI will check whether it hit AHB TX Buffer first.

BUFFERABLEEN

Enable AHB bus bufferable write access support. This field affects the last beat of AHB write access, refer for more details about AHB bufferable write.

0 (BUFFERABLEEN_0): Disabled. For all AHB write access (no matter bufferable or non-bufferable ), FlexSPI will return AHB Bus ready after all data is transmitted to External device and AHB command finished.

1 (BUFFERABLEEN_1): Enabled. For AHB bufferable write access, FlexSPI will return AHB Bus ready when the AHB command is granted by arbitrator and will not wait for AHB command finished.

PREFETCHEN

AHB Read Prefetch Enable.

READADDROPT

AHB Read Address option bit. This option bit is intend to remove AHB burst start address alignment limitation.

0 (READADDROPT_0): There is AHB read burst start address alignment limitation when flash is accessed in parallel mode or flash is wordaddressable.

1 (READADDROPT_1): There is no AHB read burst start address alignment limitation. FlexSPI will fetch more data than AHB burst required to meet the alignment requirement.

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