V104
Appendix C: UART SCC2691
C-2
MR2 (Mode Register 2):
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Channel Mode
TxRTS
CTS Enable
Tx
Stop Bit Length
(add 0.5 to cases 0-7 if channel is 5 bits/character)
00 = Normal
01 = Auto echo
10 = Local loop
11 = Remote loop
0 = no
1 = yes
0 = no
1 = yes
0 = 0.563 4 = 0.813 8 = 1.563 C = 1.813
1 = 0.625 5 = 0.875 9 = 1.625 D = 1.875
2 = 0.688 6 = 0.938 A = 1.688 E = 1.938
3 = 0.750 7 = 1.000 B = 1.750 F = 2.000
CSR (Clock Select Register):
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Receiver Clock Select
Transmitter Clock Select
when ACR[7] = 0:
0 = 50 1 = 110 2 = 134.5 3 = 200
4 = 300 5 = 600 6 = 1200 7 = 1050
8 = 2400 9 = 4800 A = 7200 B = 9600
C = 38.4k D = Timer E = MPI-16x F = MPI-1x
when ACR[7] = 1:
0 = 75 1 = 110 2 = 134.5 3 = 150
4 = 300 5 = 600 6 = 1200 7 = 2000
8 = 2400 9 = 4800 A = 7200 B = 1800
C = 19.2k D = Timer E = MPI-16x F = MPI-1x
when ACR[7] = 0:
0 = 50 1 = 110 2 = 134.5 3 = 200
4 = 300 5 = 600 6 = 1200 7 = 1050
8 = 2400 9 = 4800 A = 7200 B = 9600
C = 38.4k D = Timer E = MPI-16x F = MPI-1x
when ACR[7] = 1:
0 = 75 1 = 110 2 = 134.5 3 = 150
4 = 300 5 = 600 6 = 1200 7 = 2000
8 = 2400 9 = 4800 A = 7200 B = 1800
C = 19.2k D = Timer E = MPI-16x F = MPI-1x
CR (Command Register):
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Miscellaneous Commands
Disable
Tx
Enable
Tx
Disable
Rx
Enable
Rx
0 = no command 8 = start C/T
1 = reset MR pointer 9 = stop counter
2 = reset receiver A = assert RTSN
3 = reset transmitter B = negate RTSN
4 = reset error status C = reset MPI
5 = reset break change change INT
INT D = reserved
6 = start break E = reserved
7 = stop break F = reserved
0 = no
1 = yes
0 = no
1 = yes
0 = no
1 = yes
0 = no
1 = yes
SR (Channel Status Register):
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Received
Break
Framing
Error
Parity
Error
Overrun
Error
TxEMT
TxRDY
FFULL
RxRDY
0 = no
1 = yes
*
0 = no
1 = yes
*
0 = no
1 = yes
*
0 = no
1 = yes
0 = no
1 = yes
0 = no
1 = yes
0 = no
1 = yes
0 = no
1 = yes
Note:
* These status bits are appended to the corresponding data character in the receive FIFO. A read of the status register provides these bits
[7:5] from the top of the FIFO together with bits [4:0]. These bits are cleared by a reset error status command. In character mode they are
reset when the corresponding data character is read from the FIFO.