Rev |
Log message |
Author |
Age |
Path |
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 |
1601d 03h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
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 |
1601d 16h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
194 |
Cleaned up licensing sections |
jshamlet |
1609d 22h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
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 |
1609d 22h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
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 |
1621d 20h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
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 |
1622d 21h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
177 |
Fixed comments in RTC module |
jshamlet |
2954d 23h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
176 |
Fixed documentation errors,
Modified uSec_Tick such that it is always generated regardless of the interval. |
jshamlet |
2959d 20h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
172 |
General code cleanup |
jshamlet |
3154d 20h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
168 |
Simplified write data path logic,
Converted RTC to packed BCD,
Corrected several bugs in real time clock component, |
jshamlet |
3988d 17h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |
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 |
3996d 16h |
/open8_urisc/trunk/VHDL/o8_rtc.vhd |