STM CircleOS forum / HSE Clock Confusion

pacoblackxx · 2011-10-23 09:33:56

Hi guys,

I am working with STM32F103, and i cant understand the role of HSE Clock.

Its name implies that is an external clock, but the datasheet says that it could be bypassed, which means that it is an internal crystal, that could be bypassed with an external crystal.

So, Can i use the HSE for System clock, without an external crystal or not?

Secondly, I purchased an STM3210 evaluation board
http://www.st.com/internet/evalboard/product/204176.jsp

I saw that the embedded SD Card Holder is connected through SDIO.

I want to connect an external SD Card with SPI. Is that possible?

Thanks

pacoblackxx · 2011-10-24 06:08:11

anybody?

yrt · 2011-10-24 06:48:09

STM32 can run with internal clock (HSI) or external clock (HSE) depending on the RCC configuration.
You must have an external crystal to use HSE.

SD card can runs in SDIO or SPI mode. For this mode, the signals are connected like this:
- SD-CMD = SPI-MOSI,
- SD-D0 = SPI-MISO
- SD-D3 = Chip Select
- SD-CK = SPI-CK

# 1 2011-10-23 09:33:56 HSE Clock Confusion

HSE Clock Confusion

# 2 2011-10-24 06:08:11 HSE Clock Confusion

Re: HSE Clock Confusion

# 3 2011-10-24 06:48:09 HSE Clock Confusion

Re: HSE Clock Confusion

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