Documentation issues (GPIO IOF, UART1)

HiFive1 Rev B
1

Hello,

I would like to share two documentation issues I noticed while I was trying to connect a TFMini lidar via UART1 to a HiFive1 rev b board.

  1. In Table 52 of FE310-G002 Manual (v19p04), IO_FUNC_EN and IO_FUNC_SEL registers are not included, while they are mentioned in Section 17.8.

  2. According to Table 53 GPIO IOF Mapping, UART1_RX is mapped to GPIO18. And, according to the HiFive1 rev b pinout (Figure 5 of HiFive1 rev b getting started guid), the gpio18 is mapped to the board’s pin 2. However, based on my testing, the rx pin is actually mapped to pin 7 (gpio 23) as I can read the lidar’s data from the pin 7, not pin 2.
    On the other hand, when I use UART0 instead, I can read the lidar’s data from pin 0 (gpio 16) as described in the documents.
    So, I believe either the chip datasheet’s gpio mapping or hifive1 board’s pinmap information is incorrect.

1 Like
2

is this true? i’m having issues reading from both UART Rx lines simultaneously…

i thought i read data from UART1 Rx, but now that i’m trying to set them both up i start to doubt myself.
has anyone done this? do i have to turn off some basic configuration for this to work?