From c32de04b5d0535df406cccc25109311fb08c49ff Mon Sep 17 00:00:00 2001 From: "-T.K.-" Date: Wed, 20 Dec 2023 22:25:05 -0800 Subject: [PATCH] ADD: add inline docs --- fpga/src/main/resources/vcu118/sdboot/sd.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fpga/src/main/resources/vcu118/sdboot/sd.c b/fpga/src/main/resources/vcu118/sdboot/sd.c index c89f1556..bc1a68e8 100644 --- a/fpga/src/main/resources/vcu118/sdboot/sd.c +++ b/fpga/src/main/resources/vcu118/sdboot/sd.c @@ -25,7 +25,9 @@ #define F_CLK (TL_CLK) // SPI SCLK frequency, in kHz -#define SPI_CLK 25000 // 1250 +// We are using the 25MHz High Speed mode. If this speed is not supported by the +// SD card, consider changing to the Default Speed mode (12.5 MHz). +#define SPI_CLK 25000 // SPI clock divisor value // @see https://ucb-bar.gitbook.io/baremetal-ide/baremetal-ide/using-peripheral-devices/sifive-ips/serial-peripheral-interface-spi