In the nexys4ddr, the SD-card voltage control is implemented in external circuitry. It is an on/off controller. If you want to implement 1.8V, you still need to apply 3.3V at first, then follow the appropriate flow diagram in the SD card specification having enquired that the card supports this mode. It would be inappropriate to try to do this in the boot loader unless you plan to expand the block ram capacity quite a bit. Sent from my iPhone > On 7 Feb 2018, at 06:59, Anup Kini <anupkini(a)gmail.com&gt; wrote: > > Hi All, > > I am currently running the bare-metal selftest example. > > I get the following response: > selftest> D > sdhci_minion_hw_reset(); > sdhci_minion_hw_reset(); > *Power = 3.3V* > Card clock disabled > Trying clock div = 255 > Actual clock divider = 255 > Card clock disabled > Trying clock div = 255 > Actual clock divider = 255 > Card clock enabled > cmd timeout > ... > sd_cmd_response[38:7]:00000000 > sd_cmd_response[70:39]:00000000 > sd_cmd_response[102:71]:00000000 > sd_cmd_response[133:103]:00000000 > sd_cmd_wait:00000000 > sd_status:00000200 > sd_cmd_packet[31:0]:00000000 > sd_cmd_packet[47:32]:00000000 > sd_data_wait:00000000 > sd_transf_cnt:00000000 > sd_detect:00000000 > sd_xfr_addr:00000000 > sd_align:00000000 > clock_divider_sd_clk:00000000 > sd_cmd_arg:00000000 > sd_cmd_i:00000000 > {sd_data_start,sd_cmd_setting[2:0]}:00000000 > sd_cmd_start:00000000 > {sd_reset,sd_clk_rst,sd_data_rst,sd_cmd_rst}:00000000 > sd_blkcnt:00000000 > sd_blksize:00000000 > sd_cmd_timeout:00000000 > cmd timeout > > ... the above set is repeated infinitely. > > In the current configuration, SD Card interface is running at 1.8V > (LVCMOS18). > When can update this change ? > > I did go through the minion_helper.c -> sdhci_write() function. > The second parameter, val carries different values, but I am unable to > figure out the main header to update this change. > > > > Thanks & Regards, > Anup Kini.

On 7 Feb 2018, at 09:34, Anup Kini <anupkini(a)gmail.com&gt; wrote: Hi Jonathan, I was able to run the bare-metal hello. I am running the self test and trying to mount the sd card. selftest> m sdhci_minion_hw_reset(); sdhci_minion_hw_reset(); Power = 3.3V Card clock disabled Trying clock div = 255 Actual clock divider = 255 Card clock disabled Trying clock div = 255 Actual clock divider = 255 Card clock enabled ... cmd timeout sd_cmd_response[38:7]:00000000 sd_cmd_response[70:39]:00000000 sd_cmd_response[102:71]:00000000 sd_cmd_response[133:103]:00000000 sd_cmd_wait:00000000 sd_status:00000200 sd_cmd_packet[31:0]:00000000 sd_cmd_packet[47:32]:00000000 sd_data_wait:00000000 sd_transf_cnt:00000000 sd_detect:00000000 sd_xfr_addr:00000000 sd_align:00000000 clock_divider_sd_clk:00000000 sd_cmd_arg:00000000 sd_cmd_i:00000000 {sd_data_start,sd_cmd_setting[2:0]}:00000000 sd_cmd_start:00000000 {sd_reset,sd_clk_rst,sd_data_rst,sd_cmd_rst}:00000000 sd_blkcnt:00000000 sd_blksize:00000000 sd_cmd_timeout:00000000 cmd timeout ... repeats the above log The sd_status returns 200, rest all seem to get 0s all the time. Looking at the above log, Kindly help to figure out if the selftest is able to receive the expected response and status from the hardware. I am trying to figure out whether the hardware or the software need to be modified. Thanks & Regards, Anup Kini. > On Wed, Feb 7, 2018 at 1:09 PM, Anup Kini <anupkini(a)gmail.com&gt; wrote: > Hi Jonathan, > > I will compare with the nexys4 board and talk to the proFPGA team to check if I need to make any changes. > Thank You. > > Thanks & Regards, > Anup Kini. > >> On Wed, Feb 7, 2018 at 12:57 PM, Dr Jonathan Kimmitt <jrrk2(a)cam.ac.uk&gt; wrote: >> In the nexys4ddr, the SD-card voltage control is implemented in external circuitry. It is an on/off controller. If you want to implement 1.8V, you still need to apply 3.3V at first, then follow the appropriate flow diagram in the SD card specification having enquired that the card supports this mode. It would be inappropriate to try to do this in the boot loader unless you plan to expand the block ram capacity quite a bit. >> >> Sent from my iPhone >> >> > On 7 Feb 2018, at 06:59, Anup Kini <anupkini(a)gmail.com&gt; wrote: >> > >> > Hi All, >> > >> > I am currently running the bare-metal selftest example. >> > >> > I get the following response: >> > selftest> D >> > sdhci_minion_hw_reset(); >> > sdhci_minion_hw_reset(); >> > *Power = 3.3V* >> > Card clock disabled >> > Trying clock div = 255 >> > Actual clock divider = 255 >> > Card clock disabled >> > Trying clock div = 255 >> > Actual clock divider = 255 >> > Card clock enabled >> > cmd timeout >> > ... >> > sd_cmd_response[38:7]:00000000 >> > sd_cmd_response[70:39]:00000000 >> > sd_cmd_response[102:71]:00000000 >> > sd_cmd_response[133:103]:00000000 >> > sd_cmd_wait:00000000 >> > sd_status:00000200 >> > sd_cmd_packet[31:0]:00000000 >> > sd_cmd_packet[47:32]:00000000 >> > sd_data_wait:00000000 >> > sd_transf_cnt:00000000 >> > sd_detect:00000000 >> > sd_xfr_addr:00000000 >> > sd_align:00000000 >> > clock_divider_sd_clk:00000000 >> > sd_cmd_arg:00000000 >> > sd_cmd_i:00000000 >> > {sd_data_start,sd_cmd_setting[2:0]}:00000000 >> > sd_cmd_start:00000000 >> > {sd_reset,sd_clk_rst,sd_data_rst,sd_cmd_rst}:00000000 >> > sd_blkcnt:00000000 >> > sd_blksize:00000000 >> > sd_cmd_timeout:00000000 >> > cmd timeout >> > >> > ... the above set is repeated infinitely. >> > >> > In the current configuration, SD Card interface is running at 1.8V >> > (LVCMOS18). >> > When can update this change ? >> > >> > I did go through the minion_helper.c -> sdhci_write() function. >> > The second parameter, val carries different values, but I am unable to >> > figure out the main header to update this change. >> > >> > >> > >> > Thanks & Regards, >> > Anup Kini. >> >