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rfish.749
Associate II
Dec 19, 2019 6:14 AM UTC
Solved

Interfacing "unmuxed" SRAM/Perpherials to STM32H742ZIT which only has muxed Addr/Data pins

Are there control signals available that would allow me to "unmux" the address/data lines using external latch? I need to use the LQPF144 package that doesn't provide the separate Address and Data pins - they are muxed.

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waclawek.jan
waclawek.janBest answer
Super User
Dec 19, 2019 6:53 AM UTC

FMC_NL, confusingly called also NADV.

You may want to read the FMC chapter in RM.

JW

3 replies

waclawek.jan
waclawek.janBest answer
Super User
Dec 19, 2019 6:53 AM UTC

FMC_NL, confusingly called also NADV.

You may want to read the FMC chapter in RM.

JW

berendi
Principal
Dec 19, 2019 7:37 AM UTC

STM32H742ZIT can handle up to 26 address lines and 16 data lines without multiplexing. How much do you need, for what peripheral(s)?

Consult the pin/ball definition table in the datasheet. You'll find that all necessary pins, FMC_A0 through FMC_A25, FMC_D0 through FMC_D15, and the various control pins (find out which ones do you need from the memory/peripheral datasheet) all have a pin number in the LQFP144 column.

rfish.749
rfish.749Author
Associate II
Dec 23, 2019 6:56 PM UTC

thanks

Berendi - i typed the wrong part number - I'm using the STM32H745, so the 144 pin package doesn't have separate addr/data pins.

JW - thanks - i missed the FMC_NL signal in the RM. Seems straight forward now.