diff --git a/doc/MANUAL.md b/doc/MANUAL.md index 3171da3..931ab05 100644 --- a/doc/MANUAL.md +++ b/doc/MANUAL.md @@ -204,16 +204,16 @@ ${CHIP_ID} and ${FILE_SVF}: # Programming over USB port "US2" -There is possibility to program ULX3S SPI config flash thru +There is possibility to program ULX3S SPI config FLASH thru US2 connector and a [fork of tinyfpga bootloader](https://github.com/tinyfpga/TinyFPGA-Bootloader) loaded to FPGA, either loaded from US1 temporary to FPGA SRAM or permanently -to SPI config flash. Bootloader uses multiboot feature of ECP5 FPGA. +to SPI config FLASH. Bootloader uses multiboot feature of ECP5 FPGA. This programming option is experimental and not recommended for regular use. -ULX3S with fully functional US2 bootloader can be used without -USB-serial to JTAG chip FT231X. +ULX3S with fully functional US2 bootloader can be used to program +FPGA config FLASH without use of USB-serial chip FT231X. For bootloader convenience, it is recommented to solder D28 diode at empty placeholder located on back side near OLED and JTAG header. @@ -228,7 +228,7 @@ USB cable, a compatible PC and selected USB port and too much luck (try all). I think bootloader's USB bus error recovery handling is wrong but sometimes it just works. US2 port should enumerate as some vendor specific USB-HID USB device -and "tiyfpgasp" application can be used to write or read arbitrary +and "tinyfpgasp" application can be used to write or read arbitrary image to FPGA SPI config FLASH. User bitstream should be uploaded to byte address 0x200000 of SPI config