update README to detail cycloader usage with arty board

README.md

@@ -3,7 +3,7 @@ Utility for programming Intel/Altera Cyclone and Xilinx Serie 7
 
 Current support:
 * Trenz cyc1000 Cyclone 10 LP 10CL025 (memory and spi flash)
-* Digilent arty 35T (memory)
+* Digilent arty Artix xc7a35ti (memory and spi flash)
 
 ## compile and install
 
@@ -70,3 +70,44 @@ cycloader -b cyc1000 -r project_name_auto.rpd
 **Note about SPI flash:
 svf file used to write in flash is just a bridge between FT2232 interfaceB
 configured in SPI mode and sfl primitive used to access EPCQ SPI flash.**
+
+### ARTY
+
+To simplify further explanations, we consider the project is generated in the
+current directory.
+
+#### loading in memory:
+
+*.bit* file is the default format generated by *vivado*, so nothing special
+task must be done to generates this bitstream.
+
+__file load:__
+```bash
+cycloader -b arty *.runs/impl_1/*.bit
+```
+
+#### SPI flash:
+.mcs must be generates through vivado with a tcl script like
+```tcl
+set project [lindex $argv 0]
+
+set bitfile "${project}.runs/impl_1/${project}.bit"
+set mcsfile "${project}.runs/impl_1/${project}.mcs"
+
+write_cfgmem -format mcs -interface spix4 -size 16 \
+    -loadbit "up 0x0 $bitfile" -loaddata "" \
+    -file $mcsfile -force
+
+```
+**Note:
+*-interface spix4* and *-size 16* depends on SPI flash capability and size.**
+
+The tcl script is used with:
+```bash
+vivado -nolog -nojournal -mode batch -source script.tcl -tclargs myproject
+```
+
+__file load:__
+```bash
+cycloader -b arty *.runs/impl_1/*.mcs
+```