Fri, 18 Jan 2013 17:18:50 +0000
[memory] Emulate main memory read wrap-around
3B1s with 512K or 1MB of base memory have a decoding quirk which causes reads
to 'wrap around'. That is to say, on a 512K machine, reading from addresses 0,
512K, 1024K or 1536K will address the same RAM byte. On a 1MB machine,
addresses 0 and 1024K address the same RAM byte.
Emulating this incorrectly causes P4TEST to report an incorrect amount of
available base RAM.
1 #ifndef SIM__HEADER
2 #define SIM__HEADER
4 unsigned int m68k_read_memory_8(unsigned int address);
5 unsigned int m68k_read_memory_16(unsigned int address);
6 unsigned int m68k_read_memory_32(unsigned int address);
7 void m68k_write_memory_8(unsigned int address, unsigned int value);
8 void m68k_write_memory_16(unsigned int address, unsigned int value);
9 void m68k_write_memory_32(unsigned int address, unsigned int value);
10 void cpu_pulse_reset(void);
11 void cpu_set_fc(unsigned int fc);
12 int cpu_irq_ack(int level);
14 #endif /* SIM__HEADER */