Rev |
Log message |
Author |
Age |
Path |
190 |
Fixed a bug in CPU where RTI/RTS wasn't idling the instruction cache, causing intermittent failures where RTI would execute as RTS, corrupting the stack;
Fixed a bug in the real-time clock where the uSec tick generator would stop if the PIT timer value was left/set to 0x00. |
jshamlet |
1574d 17h |
/open8_urisc/trunk/ |
189 |
Merged changes from private repository,
added ceil_log2 function to Open8_pkg, since it is used to calculate RAM vectors,
cleaned up comments and removed local copies of the ceil_log2 function from peripherals. |
jshamlet |
1575d 18h |
/open8_urisc/trunk/ |
188 |
Added a generic to alter the behavior of RTI so that it can optionally skip restoring the general purpose flags GP4 to GP7, allowing ISR's to make persistent changes to them. Also exported these flags to the top level for use outside the CPU. |
jshamlet |
1575d 21h |
/open8_urisc/trunk/ |
187 |
Added the CPU_Halt input, only now as an input to the instruction decoder. The CPU_Halt line will assert the registered CPU_Halt_Req, which will cause the instruction decoder to abort the current instruction, reset the PC, then enter a hold state until the line is deasserted. Additionally, a very minor bug that could cause the SMSK instruction to effectively execute twice if interrupted was fixed. Lastly, cleaned up the comments even more. |
jshamlet |
1577d 17h |
/open8_urisc/trunk/ |
186 |
Merged the interrupt override logic into the case structure, simplifying how interrupts are processed. |
jshamlet |
1580d 17h |
/open8_urisc/trunk/ |
185 |
1) Fixed an apparently long-standing bug where the interrupt bit wasn't being cleared after an RTI
2) Modified the program counter logic to be simpler. It now always increments, and states control the increment using the offset field. A new set of constants was added to replace the old states.
3) Modified the ALU to always use Operand1 instead of ALU_Ctrl.Data (and removed the field in the record). A new ALU command, ALU_GMSK, was added, as it was the only instruction to set the .Data field to something other than Operand1 (Int_Mask)
4) Modified the package file so that flag names match what the assembler calls them. FL_Z is now PSR_Z, FL_GP1 is now PSR_GP4, etc.
5) Cleaned up the comments and code formatting |
jshamlet |
1580d 19h |
/open8_urisc/trunk/ |
184 |
More file/entity renaming to match private versions. |
jshamlet |
1582d 19h |
/open8_urisc/trunk/ |
183 |
Renamed core to o8_cpu to match new naming scheme |
jshamlet |
1582d 20h |
/open8_urisc/trunk/ |
182 |
Simplified the address generation logic at the expense of making LDX take one additional clock cycle. This allowed the address logic to be split out of the main state machine and simplified (greatly). During this process, a bug in SDO was found and fixed that caused it to return through the wrong pipe fill state wnen auto increment was disabled. |
jshamlet |
1582d 20h |
/open8_urisc/trunk/ |
181 |
Altered the RSP instruction to allow the stack pointed to either be restored from registers or stored to registers based on the status of a processor bit. Also modified LDX to simplify the address logic. |
jshamlet |
1583d 16h |
/open8_urisc/trunk/ |
180 |
Added additional Open8 compatible modules |
jshamlet |
1587d 20h |
/open8_urisc/trunk/ |
179 |
Replacing files accidentally deleted during check-in |
jshamlet |
1597d 15h |
/open8_urisc/trunk/ |
178 |
Adding Open8 toolset for pure assembly |
jshamlet |
1597d 16h |
/open8_urisc/trunk/ |
177 |
Fixed comments in RTC module |
jshamlet |
2907d 20h |
/open8_urisc/trunk/ |
176 |
Fixed documentation errors,
Modified uSec_Tick such that it is always generated regardless of the interval. |
jshamlet |
2912d 18h |
/open8_urisc/trunk/ |
175 |
Added 4 and 8-bit LCD interfaces with backlight and contrast DACs |
jshamlet |
2912d 23h |
/open8_urisc/trunk/ |
174 |
Added ROM/RAM wrappers |
jshamlet |
3107d 17h |
/open8_urisc/trunk/ |
173 |
Added a couple of useful interfaces for detecting button presses and clock changes. |
jshamlet |
3107d 18h |
/open8_urisc/trunk/ |
172 |
General code cleanup |
jshamlet |
3107d 18h |
/open8_urisc/trunk/ |
171 |
Fixed comments for offsets 0x0 - 0x3 to indicate the read value |
jshamlet |
3107d 18h |
/open8_urisc/trunk/ |
170 |
Added 24-bit resolution epoch timer / alarm clock |
jshamlet |
3107d 18h |
/open8_urisc/trunk/ |
169 |
Corrected issue with CMP and SBC generating an inverted carry flag and added new constants to the package file to simplify interfacing new modules. |
jshamlet |
3162d 18h |
/open8_urisc/trunk/ |
168 |
Simplified write data path logic,
Converted RTC to packed BCD,
Corrected several bugs in real time clock component, |
jshamlet |
3941d 15h |
/open8_urisc/trunk/ |
167 |
Updated CPU model; Pipelined ALU control signals to improve fMAX, corrected issue with interrupt controller priority not being obeyed, fixed bug in auto-indexing instructions where the upper register wasn't being properly incremented, cleaned up code to make the processor model easier to follow.
Added several useful modules that use the Open8 bus. |
jshamlet |
3949d 13h |
/open8_urisc/trunk/ |
166 |
fixed additional issues with range checking on PCREL relocations for open8, added test cases to verify, catch tree up with binutils datestamp 20120301 |
khays |
4513d 14h |
/open8_urisc/trunk/ |
165 |
fixed issues with PC relative fixups in the linker |
khays |
4514d 21h |
/open8_urisc/trunk/ |
164 |
Modified the data path to allow the bus to go idle while waiting for an interrupt. This makes it easier to debug code that uses the WAI instruction, as both Wr_Enable and Rd_Enable go low. |
jshamlet |
4585d 09h |
/open8_urisc/trunk/ |
163 |
sync with binutils 2.22.51.20111114 |
khays |
4622d 21h |
/open8_urisc/trunk/ |
162 |
Added optional generic to specify that the BRK instruction implements a WAit_for_Interrupt (WAI) instruction instead. Logically emulates INT, but without triggering a soft interrupt. Note that the NOP instruction maps to BRK, and will not function correctly if this option is set. |
jshamlet |
4676d 02h |
/open8_urisc/trunk/ |
161 |
synchronize binutils/ with gnu dev tree of 2.21.53.20110828 |
khays |
4699d 20h |
/open8_urisc/trunk/ |