stnolting/neorv32: v1.6.4

Bug Fixes fixed bug in WISHBONE interface: pipelined Wishbone mode did not clear STB after first transfer cycle Updates and New Features on-chip debugger: reworked JTAG signal input/output synchronization logic (#216) reworked TRNG (#212) :warning: removed WI_CTRL_CKSTEN flag (enable clock stretching) from control registers, clock-stretching is now always enabled major control unit and AKU logic optimizations; :lock: closed further illegal instruction encoding holes (system environment instructions, ALU and ALU-immediate instructions, FENCE instructions) (#204) :warning: reworked IRQ trigger logic of SPI, TWI, UART0, UART1, NELOED and SLINK; FIRQs now only trigger once when the programmed interrupt condition is met instead of triggering all the time (#202) added new peripheral module - General Purpose 32-bit Timer GPTMR (#195) What's Changed Add a Gitter chat badge to README.md by @gitter-badger in https://github.com/stnolting/neorv32/pull/196 Add general purpose timer GPTMR by @stnolting in https://github.com/stnolting/neorv32/pull/195 Add cyclone2 legacy mem-files by @stnolting in https://github.com/stnolting/neorv32/pull/198 [ci] use option 'pacboy' to simplify workflow 'Windows' by @umarcor in https://github.com/stnolting/neorv32/pull/201 Rework peripheral's FIRQ triggering by @stnolting in https://github.com/stnolting/neorv32/pull/202 Added neorv32-examples by @emb4fun in https://github.com/stnolting/neorv32/pull/205 CPU logic optimization by @stnolting in https://github.com/stnolting/neorv32/pull/204 [TWI] remove clock-stretching enable flag by @stnolting in https://github.com/stnolting/neorv32/pull/209 setups/osflow/Makefile: support overriding variables by @umarcor in https://github.com/stnolting/neorv32/pull/214 Rework TRNG module by @stnolting in https://github.com/stnolting/neorv32/pull/212 Added a example serial terminal program for Linux by @qwqw330 in https://github.com/stnolting/neorv32/pull/215 [On-Chip Debugger] Fix JTAG timing by @stnolting in https://github.com/stnolting/neorv32/pull/216 Add iCEBreaker Board to the osflow by @lab-mathias-claussen in https://github.com/stnolting/neorv32/pull/217 Adding the possibility of indicate external sources throw a enviromen… by @zipotron in https://github.com/stnolting/neorv32/pull/213 New Contributors @gitter-badger made their first contribution in https://github.com/stnolting/neorv32/pull/196 @emb4fun made their first contribution in https://github.com/stnolting/neorv32/pull/205 @qwqw330 made their first contribution in https://github.com/stnolting/neorv32/pull/215 @lab-mathias-claussen made their first contribution in https://github.com/stnolting/neorv32/pull/217 Full Changelog: https://github.com/stnolting/neorv32/compare/v1.6.3...v1.6.