URL
https://opencores.org/ocsvn/ion/ion/trunk
Subversion Repositories ion
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- This comparison shows the changes necessary to convert path
/ion
- from Rev 2 to Rev 3
- ↔ Reverse comparison
Rev 2 → Rev 3
/trunk/doc/ion_project.txt
79,7 → 79,7
- RTE instruction. |
- Most of the CP0 registers and of course all of the CP1. |
- External interrupts. |
- Syscall instruction (just aborts next instruction and jal's to 0x3c). |
- Syscall instruction (very limited implementation). |
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### Things implemented but not tested. |
- Memory pause input. |
512,13 → 512,12
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Exceptions are unimplemented yet. |
Instructions 'break' and 'syscall', which should trigger an exception, do |
instead a jal to a fixed address (0x03c), which is the same as Plasma does. |
instead a jump to a fixed address (0x03c), like Plasma does. |
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The only pecularity is that they save the address of the next |
instruction to register $ra (unlike jal, which would save the second to |
next) and they abort the next instruction. They save the EPC register as |
specified too, though the epc register is not used by any instruction other |
than mfc0. |
instruction to register ep (unlike jal, which would save the second to |
next to $ra) and they abort the next instruction. The epc register is not |
used by any instruction other than mfc0. |
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The abort is performed by disabling register bank writes for the ALU stage |
following the ALU stage where the exception is triggered -- we're talking |