SCC Programming Reference
MOTOROLA
MC68360 USER’S MANUAL
E-15
E.2 UART PROGRAMMING REFERENCE SECTION
This subsection deals with the registers and parameters required to program an SCC as a
UART. At the end of this subsection is a generic algorithm for programming the SCC.
E.2.1 UART Programming Model
The programming model and memory map for the UART protocol is shown in Table E-2. The
offsets for each SCC are given above each table. Some parameters are common to all pro-
tocols. The UART parameters are shown for those entries that are protocol specific. Table
E-2(b) depicts the general and protocol-specific parameter RAM for each SCC. The SCC
registers are shown in Table E-2(c), and the communications processor registers are shown
in Table E-2(d). Note that reserved bits in registers should be written as zeros.
NOTE: The offset is from the MC68302
base address + ($400 for SCC1, $500 for SCC2, or $600 for SCC3).
Table E-1 (a). UART Programming Model
Receive and Transmit Buffer Descriptors for SCCx
Initialized
by User
Yes
Offset
Hex
00
02
04
06
08
0A
0C
0E
10
12
14
16
18
1A
1C
1E
20
22
24
26
28
2A
2C
2E
30
32
34
36
38
3A
3C
3E
Name
Initialized
by User
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Offset
Hex
40
42
44
46
48
4A
4C
4E
50
52
54
56
58
5A
5C
5E
60
62
64
66
68
6A
6C
6E
70
72
74
76
78
7A
7C
7E
Name
Yes
Yes
Yes
Rx BD 0 Control/Status
Rx BD 0 Data Count
Rx BD 0 Data Pointer (High Word)
Rx BD 0 Data Pointer (Low Word)
Rx BD 1 Control/Status
Rx BD 1 Data Count
Rx BD 1 Data Pointer (High Word)
Rx BD 1 Data Pointer (Low Word)
Rx BD 2 Control/Status
Rx BD 2 Data Count
Rx BD 2 Data Pointer (High Word)
Rx BD 2 Data Pointer (Low Word)
Rx BD 3 Control/Status
Rx BD 3 Data Count
Rx BD 3 Data Pointer (High Word)
Rx BD 3 Data Pointer (Low Word)
Rx BD 4 Control/Status
Rx BD 4 Data Count
Rx BD 4 Data Pointer (High Word)
Rx BD 4 Data Pointer (Low Word)
Rx BD 5 Control/Status
Rx BD 5 Data Count
Rx BD 5 Data Pointer (High Word)
Rx BD 5 Data Pointer (Low Word)
Rx BD 6 Control/Status
Rx BD 6 Data Count
Rx BD 6 Data Pointer (High Word)
Rx BD 6 Data Pointer (Low Word)
Rx BD 7 Control/Status
Rx BD 7 Data Count
Rx BD 7 Data Pointer (High Word)
Rx BD 7 Data Pointer (Low Word)
Tx BD 0 Control/Status
Tx BD 0 Data Count
Tx BD 0 Data Pointer (High Word)
Tx BD 0 Data Pointer (Low Word)
Tx BD 1 Control/Status
Tx BD 1 Data Count
Tx BD 1 Data Pointer (High Word)
Tx BD 1 Data Pointer (Low Word)
Tx BD 2 Control/Status
Tx BD 2 Data Count
Tx BD 2 Data Pointer (High Word)
Tx BD 2 Data Pointer (Low Word)
Tx BD 3 Control/Status
Tx BD 3 Data Count
Tx BD 3 Data Pointer (High Word)
Tx BD 3 Data Pointer (Low Word)
Tx BD 4 Control/Status
Tx BD 4 Data Count
Tx BD 4 Data Pointer (High Word)
Tx BD 4 Data Pointer (Low Word)
Tx BD 5 Control/Status
Tx BD 5 Data Count
Tx BD 5 Data Pointer (High Word)
Tx BD 5 Data Pointer (Low Word)
Tx BD 6 Control/Status
Tx BD 6 Data Count
Tx BD 6 Data Pointer (High Word)
Tx BD 6 Data Pointer (Low Word)
Tx BD 7 Control/Status
Tx BD 7 Data Count
Tx BD 7 Data Pointer (High Word)
Tx BD 7 Data Pointer (Low Word)
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes