Rev |
Log message |
Author |
Age |
Path |
215 |
More code cleanup |
jshamlet |
1575d 15h |
/open8_urisc/ |
214 |
Initial add of some older code |
jshamlet |
1579d 13h |
/open8_urisc/ |
213 |
Code and comment cleanup |
jshamlet |
1579d 14h |
/open8_urisc/ |
212 |
Fixed issue with rewritten epoch timer not clearing alarm on set point write. |
jshamlet |
1579d 20h |
/open8_urisc/ |
211 |
Ok, this time with feeling. Timer should now properly reset on interval update. |
jshamlet |
1580d 18h |
/open8_urisc/ |
210 |
Modified the timers to reset on new interval write. This avoids an issue in the original design where the timer had to reach zero before updating, potentially causing unwanted interrupts.
Also added a flag to the CPU to allow interrupts to be processed sequentially based on the state of the I bit. This one is set to false by default, as it is a significant change in interrupt behavior. Long, and reentrant, ISRs can clear the I bit prematurely to allow themselves to be interrupted.
Lastly, added the I bit to the exported flags for possible use in memory protection schemes. |
jshamlet |
1580d 20h |
/open8_urisc/ |
209 |
Fixed an issue in the PIT timer that caused an immediate interrupt on interval write,
Fixed an issue in the epoch timer that resulted in a spurious interrupt due to extra LSB's being set by default in the set point register,
While cleaning elsewhere, founding a spacing issue in the CPU HDL,
Added a 4k ROM and MW core. |
jshamlet |
1581d 09h |
/open8_urisc/ |
208 |
Removed unnecessary package references |
jshamlet |
1581d 18h |
/open8_urisc/ |
207 |
Added a simple 8-bit, fixed asynchronous serial interface with compile time settable bit-rate, parity enable, and parity mode generics. |
jshamlet |
1582d 11h |
/open8_urisc/ |
206 |
Merged interrupt logic with other clocked process. |
jshamlet |
1586d 06h |
/open8_urisc/ |
205 |
More code and comment cleanup for the new SDLC engine |
jshamlet |
1586d 06h |
/open8_urisc/ |
204 |
Fixed more incorrect comments |
jshamlet |
1586d 07h |
/open8_urisc/ |
203 |
Removed an extra delay FF from the bitclock rising edge signal for the clock slave configuration to better center the rising edge pulse on the receive signal. |
jshamlet |
1586d 13h |
/open8_urisc/ |
202 |
Fixed receiver bug that caused false flag detection,
Split the large sdlc_serial_ctrl entity into sub-entities to make debugging easier. |
jshamlet |
1586d 14h |
/open8_urisc/ |
201 |
Fixed comments regarding RX Checksum location |
jshamlet |
1588d 11h |
/open8_urisc/ |
200 |
Renamed dual-port buffer to match other entities. |
jshamlet |
1588d 11h |
/open8_urisc/ |
199 |
Added monitor ram for debugging and fixed issue with dual-port read path. |
jshamlet |
1588d 11h |
/open8_urisc/ |
198 |
Removed debugging memory |
jshamlet |
1588d 19h |
/open8_urisc/ |
197 |
Fixed incorrect comments |
jshamlet |
1588d 20h |
/open8_urisc/ |
196 |
Modified the update logic to allow direct writes to offset 0xFE for refreshing the clock status. This way, any write to the clock status register will immediately be undone. (Writing 0x00 to offset 0xFF is once-more ignored) |
jshamlet |
1588d 20h |
/open8_urisc/ |
195 |
Added dual-port RAM core for SDLC interface. |
jshamlet |
1589d 15h |
/open8_urisc/ |
194 |
Cleaned up licensing sections |
jshamlet |
1589d 15h |
/open8_urisc/ |
193 |
Fixed incorrect comment in o8_alu16.vhd. The value of the write to 0x1F doesn't matter, as the write itself triggers the calculation. |
jshamlet |
1589d 15h |
/open8_urisc/ |
192 |
Added SDLC packet engine |
jshamlet |
1589d 16h |
/open8_urisc/ |
191 |
Cleaned up comments, added back the OPEN8_NULLBUS constant, and added some new modules for ADCs and LCD displays.
Also made the button input module more configurable by moving the debounce code to a separate entity and using generics to instantiate it. |
jshamlet |
1589d 16h |
/open8_urisc/ |
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 |
1601d 13h |
/open8_urisc/ |
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 |
1602d 14h |
/open8_urisc/ |
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 |
1602d 17h |
/open8_urisc/ |
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 |
1604d 13h |
/open8_urisc/ |
186 |
Merged the interrupt override logic into the case structure, simplifying how interrupts are processed. |
jshamlet |
1607d 13h |
/open8_urisc/ |