 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
MC68302PV20 Datasheet(PDF) 44 Page - Motorola, Inc |
|
||||||||||||||||||||||||||||||
MC68302PV20 Datasheet(HTML) 44 Page - Motorola, Inc |
|
|
44 / 480 page 
MC68000/MC68008 Core 2-14 MC68302 USER’S MANUAL MOTOROLA CFC—Compare Function Code 0 = The FC bits in the BAR are ignored. Accesses to the IMP 4K-byte block occur with- out comparing the FC bits. 1 = The FC bits in the BAR are compared. The address space compare logic uses the FC bits to detect address matches. Bits 11–0—Base Address The high address field is contained in bit 11–0 of the BAR. These bits are used to set the starting address of the dual-port RAM. The address compare logic uses only the most sig- nificant bits to cause an address match within its block size. 2.8 MC68302 MEMORY MAP The following tables show the additional registers added to the M68000 to make up the MC68302. All of the registers are memory-mapped. Four entries in the M68000 exception vectors table (located in low RAM) are reserved for addresses of system configuration reg- isters (see Table 2-6) that reside on-chip. These registers have fixed addresses of $0F0– $0FF. All other on-chip peripherals occupy a 4K-byte relocatable address space. When an on-chip register or peripheral is accessed, the internal access (IAC) pin is asserted. *Reset only upon a total system reset. The internal 1176-byte dual-port RAM has 576 bytes of system RAM (see Table 2-7) and 576 bytes of parameter RAM (see Table 2-8). The parameter RAM contains the buffer descriptors for each of the three SCC channels, the SCP, and the two SMC channels. The memory structures of the three SCC channels are Table 2-6. System Configuration Register Address Name Width Description Reset Value $0F0 RES 16 Reserved $0F2 * BAR 16 Base Address Register BFFF $0F4 * SCR 32 System Control Register 0000 0F00 $0F8 RES 16 Reserved $0FA CKCR 16 Clock Control Register 0000 $0FC RES 32 Reserved Table 2-7. System RAM Address Width Block Description Base + 000 • • • Base + 23F 576 Bytes RAM User Data Memory Base +240 • • • Base + 3FF Reserved (Not Implemented) |
English ▼
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
