Added release notes for version 1.5.

release-notes.md

@@ -1,3 +1,71 @@
+# SweRV RISC-V Core<sup>TM</sup> 1.5 from Western Digital
+## Release Notes
+
+
+This is a bug-fix and performance-improvement release.  No new functionality
+is added to the SweRV core.
+
+
+## Bug fixes:
+
+1. Hart incorrectly cleared dmcontrol.dmactive on reset (reported by
+   Codasip).
+2. Hart never asserted the dmstatus.allrunning signal on reset which
+   caused a timeout in OpenOCD (reported by Codasip).
+3. Debug module failed to auto-increment register on system-bus access
+   of size 64-bit (reported by Codasip).
+4. The core_rst_n signal was incorrectly connected (reported by Codasip).
+5. Moudule/instance renamed for tool compatibility.
+6. The program counter was getting corrupted when the load/store unit
+   indicated both a single-bit and a double-bit error in the same
+   cycle.
+7. The MSTATUS control register was not being updated as expected when
+   both a non-maskable-interrupt and an MSTATUS-write happened in the
+   same cycle.
+8. Write to SBDATA0 was not starting an system-bus write access when
+   sbreadonaddr/sbreadondata is set.
+9. Minstret was incorrectly counting ecall/ebreak instructions
+10. The dec_tlu_mpc_halted_only signal was not set for MPC halt after
+    reset.
+11. The MEPC control register was not being updated when a
+    firmware-halt request was followed by a timer interrupt.
+12. The MINSTRETH control register was being incremented when
+    performance counters were disabled.
+13. Bus driver contained combinational logic from multiple clock
+    domains that sometimes caused a glitch.
+14. System bus reads were always being made with 64-bit size for the
+    AXI bus which is incorrect for IO access.
+15. DCCM single bit errors were counted for instruction that did not
+    commit.
+16. ICCM Single Bit Errors were double counted.
+17. Load/store unit was not detecting access faults when DCCM and PIC
+    memories are next to each other.
+18. Single bit ECC errors on data load were not always corrected in
+    the DCCM.
+19. ECC single bit error were not always corrected in the DCCM for DMA
+    access.
+20. Single bit Errors detected while reading ICCM through DMA were not
+    being corrected in memory.
+
+
+## Improvements:
+
+1. Improved performance by removing redundant term in decode stall
+   logic.
+2. Reduced power used by the ICCM memory arrays.
+
+
+## Testbench Improvements:
+
+1. AXI4 and AHB-Lite support.
+2. Updated bus memory to be persistent and handle larger programs.
+3. Makefile supports ability to run with source or pre-generated hex
+   files.
+4. Makefile supports targets for coremarks benchmark (issue #25).
+5. Questa support in Makefile (Issue #19).
+
+
+
 # SweRV RISC-V Core<sup>TM</sup> 1.4 from Western Digital
 ## Release Notes
 Move declarations to top of Verilog file to fix fpga compile issues.