LPC Microcontrollers中的主题 Low performance USB MSC https://community.nxp.com/t5/LPC-Microcontrollers/Low-performance-USB-MSC/m-p/699241#M28157 <HTML><HEAD></HEAD><BODY><P>Hi, with a LPC54600 Xpresso board, I met a problem that the read performance of USB MSC example is very low.</P><P>My configuration:</P><P>SDK2.20</P><P>IAR 8.11.2, compiled in high speed</P><P>SD Card : Sandisk 16G Class 10</P><P>Project : usb_examples\usb_device_msc_sdcard</P><BLOCKQUOTE class="jive_macro_quote jive-quote jive_text_macro"><P>#define USB_DEVICE_CONFIG_LPCIP3511HS (1U)</P></BLOCKQUOTE><P>At first I got only 1.2MB/s read and 350KB/s write, so I changed the MSC packet size:</P><BLOCKQUOTE class="jive_macro_quote jive-quote jive_text_macro"><P>#define USB_DEVICE_MSC_WRITE_BUFF_SIZE (16384U)<BR />#define USB_DEVICE_MSC_READ_BUFF_SIZE (16384U)</P></BLOCKQUOTE><P>Now the write speed is increased to 3.5MB/s, but the read speed is decreased to 800KB/s !</P><P>On&nbsp;STM32F746 this SD card has a read speed of 7MB/s with their awful SDIO implementation.</P><P>Has anyone met this problem ?</P></BODY></HTML> Mon, 11 Sep 2017 15:01:05 GMT zixunli 2017-09-11T15:01:05Z Low performance USB MSC https://community.nxp.com/t5/LPC-Microcontrollers/Low-performance-USB-MSC/m-p/699241#M28157 <HTML><HEAD></HEAD><BODY><P>Hi, with a LPC54600 Xpresso board, I met a problem that the read performance of USB MSC example is very low.</P><P>My configuration:</P><P>SDK2.20</P><P>IAR 8.11.2, compiled in high speed</P><P>SD Card : Sandisk 16G Class 10</P><P>Project : usb_examples\usb_device_msc_sdcard</P><BLOCKQUOTE class="jive_macro_quote jive-quote jive_text_macro"><P>#define USB_DEVICE_CONFIG_LPCIP3511HS (1U)</P></BLOCKQUOTE><P>At first I got only 1.2MB/s read and 350KB/s write, so I changed the MSC packet size:</P><BLOCKQUOTE class="jive_macro_quote jive-quote jive_text_macro"><P>#define USB_DEVICE_MSC_WRITE_BUFF_SIZE (16384U)<BR />#define USB_DEVICE_MSC_READ_BUFF_SIZE (16384U)</P></BLOCKQUOTE><P>Now the write speed is increased to 3.5MB/s, but the read speed is decreased to 800KB/s !</P><P>On&nbsp;STM32F746 this SD card has a read speed of 7MB/s with their awful SDIO implementation.</P><P>Has anyone met this problem ?</P></BODY></HTML> Mon, 11 Sep 2017 15:01:05 GMT https://community.nxp.com/t5/LPC-Microcontrollers/Low-performance-USB-MSC/m-p/699241#M28157 zixunli 2017-09-11T15:01:05Z