
MC68000/MC68008 Core
MOTOROLA
MC68302 USER’S MANUAL
2-15
identical. When any SCC, SCP, or SMC channel buffer descriptors or parameters are not
used, their parameter RAM area can be used for additional memory. For detailed informa-
tion about the use of the buffer descriptors and protocol parameters in a specific protocol,
see 4.5 Serial Communication Controllers (SCCs). Base + 67E contains the MC68302 revi-
sion number. Revision A parts (mask 1B14M) correspond to the value $0001. Revision B
parts (mask 2B14M and 3B14M which are described in this manual) correspond to the value
$0002. Revision C and D parts have revision number $0003.
Table 2-8. Parameter RAM
Address
Width
Block
Description
Base + 400
Base + 408
Base + 410
Base + 418
Base + 420
Base + 428
Base + 430
Base + 438
Base + 440
Base + 448
Base + 450
Base + 458
Base + 460
Base + 468
Base + 470
Base + 478
Base + 480
Base + 4BF
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
SCC1
Rx BD 0
Rx BD 1
Rx BD 2
Rx BD 3
Rx BD 4
Rx BD 5
Rx BD 6
Rx BD 7
Tx BD 0
Tx BD 1
Tx BD 2
Tx BD 3
Tx BD 4
Tx BD 5
Tx BD 6
Tx BD 7
SCC1
Specific Protocol Parameters
Base + 4C0
Base + 4FF
Base + 500
Base + 508
Base + 510
Base + 518
Base + 520
Base + 528
Base + 530
Base + 538
Base + 540
Base + 548
Base + 550
Base + 558
Base + 560
Base + 568
Base + 570
Base + 578
Reserved
(Not Implemented)
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
4 Word
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
SCC2
Rx BD 0
Rx BD 1
Rx BD 2
Rx BD 3
Rx BD 4
Rx BD 5
Rx BD 6
Rx BD 7
Tx BD 0
Tx BD 1
Tx BD 2
Tx BD 3
Tx BD 4
Tx BD 5
Tx BD 6/DRAM Refresh
Tx BD 7/DRAM Refresh