Translation Reload Examples - Motorola MPC823e Reference Manual

Memory Management Unit
11.8.1.1 TRANSLATION RELOAD EXAMPLES. The following are code examples for
generating the real page number using a two-level tree page table structure. The first
example is for a data TLB reload and the second is for an instruction TLB reload. Notice that
the following assumptions are made:
• M_TWB holds the base pointer to the first level table.
• Both instruction and data address translation is turned off (MSR
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itlb_swtw mtspr
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M_TW, R1 # save R1
R1, M_TWB # load R1 with level one pointer
R1, (R1) # Load level one page entry
MD_TWC,R1 # save level two base pointer and
# level one attributes
R1, MD_TWC # load R1 with level two pointer
# while taking into account the
# page size
R1, (R1) # Load level two page entry
MD_RPN, R1 # Write TLB entry
R1, M_TW # restore R1
M_TW, R1 # save R1
R1, SRR0 # load R1 with instruction miss
# effective address (the same data
# may be taken from the MI_EPN
# register)
MD_EPN, R1 # save instruction miss effective
# address in MD_EPN
R1, M_TWB # load R1 with level one pointer
R1, (R1) # Load level one page entry
MI_TWC,R1 # save level one attributes
MD_TWC,R1 # save level two base pointer
R1, MD_TWC # load R1 with level two pointer
# while taking into account the
# page size
R1, (R1) # Load level two page entry
MI_RPN, R1 # Write TLB entry
R1, M_TW # restore R1
MPC823e REFERENCE MANUAL
=0 and MSR =0).
IR DR
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