folkert/KEK
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

MMR0 (bits 10 & 11 always 0) fix

Browse source
This commit is contained in:
folkert van heusden 2022-03-22 10:20:20 +01:00
parent eeed41c62e
commit ff8539565f
1 changed files with 3 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
bus.cpp
View file

@ -206,12 +206,8 @@ uint16_t bus::read(const uint16_t a, const bool word_mode, const bool use_prev)
}
else {
if (a == 0177572) {
uint16_t t = (run_mode << 5) | // kernel == 00
((c -> getRegister(7) >> 13) << 1) | // page nr
0 // MMU enabled
;
D(fprintf(stderr, "read MMU MMR0 %o\n", t);)
return t;
D(fprintf(stderr, "read MMR0\n");)
return MMR0;
}
if (a == 0177574) { // MMR1
@ -433,7 +429,7 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
if (a == 0177572) { // MMR0
D(fprintf(stderr, "write set MMR0: %o\n", value);)
MMR0 = value;
MMR0 = value & ~(3 << 10); // bit 10 & 11 always read as 0
return MMR0;
}