# FE310-G000 manual is missing the GPIO IOF mappings

**URL:** https://forums.sifive.com/t/fe310-g000-manual-is-missing-the-gpio-iof-mappings/2253
**Category:** HiFive1 Rev B
**Created:** [April 24, 2019, 8:54am UTC](https://forums.sifive.com/t/fe310-g000-manual-is-missing-the-gpio-iof-mappings/2253 "2019-04-24T08:54:42Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![nimblemachines](https://avatars.discourse-cdn.com/v4/letter/n/e95f7d/32.png) [@nimblemachines](https://forums.sifive.com/u/nimblemachines)
#### Post date: [April 24, 2019, 8:54am UTC](https://forums.sifive.com/t/fe310-g000-manual-is-missing-the-gpio-iof-mappings/2253/1 "2019-04-24T08:54:42Z")

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This is really a message for the SiFive documentation team.

After much searching, I found a set of IOF mappings for the FE310-G002 (in the -G002 manual). I’m going to assume that things are similar for the G000, namely:

UART and SPI pins are all IOF0 (IOF\_SEL=0)  
PWM pins are all IOF1 (IOF\_SEL=1)

Maybe update the -G000 manual to include these? I was really going crazy trying to find this info! I even tracked down a copy of the Freedom E300 Platform manual hoping to find my answers there, but alas, no!

Thanks,

- David

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### Author: ![yksflip](https://avatars.discourse-cdn.com/v4/letter/y/58f4c7/32.png) [@yksflip](https://forums.sifive.com/u/yksflip)
#### Post date: [May 11, 2019, 12:06pm UTC](https://forums.sifive.com/t/fe310-g000-manual-is-missing-the-gpio-iof-mappings/2253/2 "2019-05-11T12:06:03Z")

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Hey David!  
Did you manage to figure out the actual memory addresses of the IOF\_EN and IOF\_SEL register?

Edit:  
found it!  
it’s defined in the src/drivers/sifive,gpio0.c

```auto
#define GPIO_IOF_EN (0x38)
#define GPIO_IOF_SEL (0x3C)

```